ansible/gen_certs: Fix regression when HTTP_PROXY is not set
ansible/gen_certs: Fix regression when HTTP_PROXY is not set

Regression from 46131210fc99fe84e121f24987f0c1669f277710 when
`http_proxy` is *not* defined.

Ansible tried to quote the undefined variable, and it ended up breaking like:

```
Could not resolve proxy: {# https_proxy #}; Name or service not known
```

spxtr/contrib,tmc/contrib,Q-Lee/contrib,upmc-enterprises/contrib,thockin/contrib,luxas/contrib,morganwu277/contrib,caesarxuchao/contrib,Wattpad/kubernetes-contrib,andrew-j-price/contrib,gouyang/contrib,jfchevrette/contrib,andrew-j-price/contrib,timstclair/kube-contrib,lavalamp/contrib,girishkalele/contrib,cdemers/contrib,gmarek/contrib,piosz/contrib,aledbf/contrib,andrew-j-price/contrib,rmmh/kubernetes-contrib,ixdy/kubernetes-contrib,Q-Lee/contrib,jfchevrette/kubernetes-contrib,ixdy/contrib,lewislyou/contrib,fcvarela/contrib,devlinmr/contrib,jfchevrette/kubernetes-contrib,gmarek/contrib,mikedanese/contrib,jdavis7257/contrib,piosz/contrib,mikedanese/contrib,danehans/contrib,gouyang/contrib,gouyang/contrib,cdemers/contrib,krousey/contrib,endocode/contrib,hongchaodeng/contrib,marketlogicsoftware/contrib,timstclair/kube-contrib,jasonbishop/contrib,danushkaf/contrib,danushkaf/contrib,krzyzacy/contrib,gmarek/contrib,morganwu277/contrib,foxish/contrib,endocode/contrib,olark/kubernetes-contrib,devlinmr/contrib,k8s-packages-power/contrib,moul/contrib,jdavis7257/contrib,simonswine/kubernetes-contrib,pwittrock/contrib,olark/kubernetes-contrib,vishpat/contrib,eastbanctech/kubernetes-contrib,xialonglee/contrib,kokhang/contrib,Arano-kai/kubernetes-contrib,widgetpl/contrib,lewislyou/contrib,davidopp/contrib,Q-Lee/contrib,pwittrock/contrib,ixdy/kubernetes-contrib,stephenrlouie/contrib,timstclair/kube-contrib,fabioy/contrib,olark/kubernetes-contrib,rmmh/kubernetes-contrib,remoe/contrib,foxish/contrib,foxish/contrib,gmarek/contrib,gemini-project/contrib,jasonbrooks/contrib,kokhang/contrib,adamschaub/contrib,andrew-j-price/contrib,adamschaub/contrib,jojimt/contrib,eastbanctech/kubernetes-contrib,xialonglee/contrib,olark/kubernetes-contrib,davidopp/contrib,rmmh/kubernetes-contrib,davidopp/contrib,krousey/contrib,devlinmr/contrib,davidopp/contrib,widgetpl/contrib,jasonbishop/contrib,upmc-enterprises/contrib,x13n/contrib,grodrigues3/contrib,lavalamp/contrib,jdavis7257/contrib,freehan/contrib,hongchaodeng/contrib,thockin/contrib,krzyzacy/contrib,vishpat/contrib,chiradeep/contrib,luxas/contrib,stephenrlouie/contrib,adamschaub/contrib,widgetpl/contrib,lavalamp/contrib,danushkaf/contrib,jasonbrooks/contrib,tmc/contrib,stephenrlouie/contrib,kskalski/contrib,morganwu277/contrib,upmc-enterprises/contrib,lewislyou/contrib,rchicoli/kubernetes-contrib,x13n/contrib,girishkalele/contrib,Arano-kai/kubernetes-contrib,simonswine/kubernetes-contrib,stephenrlouie/contrib,luxas/contrib,girishkalele/contrib,fcvarela/contrib,endocode/contrib,atosatto/kubernetes-contrib,kow3ns/contrib,thockin/contrib,morganwu277/contrib,lavalamp/contrib,gmarek/contrib,jfchevrette/contrib,jfchevrette/contrib,timstclair/kube-contrib,davidopp/contrib,jdavis7257/contrib,verb/contrib,krzyzacy/contrib,eastbanctech/kubernetes-contrib,Wattpad/kubernetes-contrib,fcvarela/contrib,fabioy/contrib,jasonbrooks/contrib,spxtr/contrib,moul/contrib,Pensu/contrib,eparis/contrib,verb/contrib,micheleorsi/contrib,thockin/contrib,Wattpad/kubernetes-contrib,remoe/contrib,upmc-enterprises/contrib,fcvarela/contrib,simonswine/kubernetes-contrib,pwittrock/contrib,danushkaf/contrib,upmc-enterprises/contrib,upmc-enterprises/contrib,ixdy/kubernetes-contrib,jasonbishop/contrib,danehans/contrib,Pensu/contrib,ixdy/kubernetes-contrib,olark/kubernetes-contrib,jcmoraisjr/k8s-contrib,Arano-kai/kubernetes-contrib,widgetpl/contrib,widgetpl/contrib,lavalamp/contrib,rmmh/kubernetes-contrib,ingvagabund/contrib,Wattpad/kubernetes-contrib,rchicoli/kubernetes-contrib,lewislyou/contrib,pwittrock/contrib,danehans/contrib,x13n/contrib,vishpat/contrib,eastbanctech/kubernetes-contrib,fabioy/contrib,atosatto/kubernetes-contrib,devlinmr/contrib,rmmh/kubernetes-contrib,micheleorsi/contrib,gemini-project/contrib,krzyzacy/contrib,ingvagabund/contrib,foxish/contrib,freehan/contrib,atosatto/kubernetes-contrib,remoe/contrib,lavalamp/contrib,kskalski/contrib,kokhang/contrib,jcmoraisjr/k8s-contrib,gemini-project/contrib,ixdy/kubernetes-contrib,lewislyou/contrib,gouyang/contrib,ingvagabund/contrib,hongchaodeng/contrib,foxish/contrib,xialonglee/contrib,micheleorsi/contrib,andrew-j-price/contrib,Arano-kai/kubernetes-contrib,jfchevrette/contrib,remoe/contrib,aknuds1/contrib,cdemers/contrib,kokhang/contrib,jasonbrooks/contrib,krousey/contrib,micheleorsi/contrib,krousey/contrib,jfchevrette/contrib,micheleorsi/contrib,jasonbishop/contrib,freehan/contrib,cdemers/contrib,Pensu/contrib,eparis/contrib,mikedanese/contrib,cdemers/contrib,gemini-project/contrib,vishpat/contrib,tmc/contrib,vishpat/contrib,chiradeep/contrib,spxtr/contrib,Pensu/contrib,kow3ns/contrib,jdavis7257/contrib,chiradeep/contrib,jfchevrette/kubernetes-contrib,k8s-packages-power/contrib,aledbf/contrib,marketlogicsoftware/contrib,tmc/contrib,luxas/contrib,freehan/contrib,danehans/contrib,tmc/contrib,moul/contrib,kskalski/contrib,eastbanctech/kubernetes-contrib,chiradeep/contrib,hongchaodeng/contrib,Q-Lee/contrib,ingvagabund/contrib,Q-Lee/contrib,spxtr/contrib,jfchevrette/kubernetes-contrib,rchicoli/kubernetes-contrib,aledbf/contrib,x13n/contrib,davidopp/contrib,caesarxuchao/contrib,olark/kubernetes-contrib,piosz/contrib,marketlogicsoftware/contrib,aknuds1/contrib,fabioy/contrib,kskalski/contrib,piosz/contrib,Arano-kai/kubernetes-contrib,jasonbishop/contrib,freehan/contrib,spxtr/contrib,jojimt/contrib,gmarek/contrib,chiradeep/contrib,eparis/contrib,adamschaub/contrib,k8s-packages-power/contrib,jasonbrooks/contrib,verb/contrib,spxtr/contrib,stephenrlouie/contrib,fabioy/contrib,jasonbishop/contrib,aledbf/contrib,Pensu/contrib,ixdy/contrib,rchicoli/kubernetes-contrib,atosatto/kubernetes-contrib,k8s-packages-power/contrib,remoe/contrib,aledbf/contrib,grodrigues3/contrib,Pensu/contrib,vishpat/contrib,gemini-project/contrib,simonswine/kubernetes-contrib,caesarxuchao/contrib,freehan/contrib,aknuds1/contrib,rchicoli/kubernetes-contrib,atosatto/kubernetes-contrib,kow3ns/contrib,endocode/contrib,widgetpl/contrib,jojimt/contrib,jasonbrooks/contrib,x13n/contrib,simonswine/kubernetes-contrib,kow3ns/contrib,moul/contrib,fcvarela/contrib,gouyang/contrib,Wattpad/kubernetes-contrib,kokhang/contrib,kskalski/contrib,jojimt/contrib,ingvagabund/contrib,eparis/contrib,eparis/contrib,grodrigues3/contrib,adamschaub/contrib,grodrigues3/contrib,chiradeep/contrib,eastbanctech/kubernetes-contrib,ixdy/contrib,girishkalele/contrib,marketlogicsoftware/contrib,devlinmr/contrib,xialonglee/contrib,mikedanese/contrib,danehans/contrib,kow3ns/contrib,jcmoraisjr/k8s-contrib,hongchaodeng/contrib,chiradeep/contrib,kow3ns/contrib,gouyang/contrib,grodrigues3/contrib,endocode/contrib,kokhang/contrib,devlinmr/contrib,rmmh/kubernetes-contrib,cdemers/contrib,luxas/contrib,jfchevrette/kubernetes-contrib,caesarxuchao/contrib,verb/contrib,marketlogicsoftware/contrib,simonswine/kubernetes-contrib,micheleorsi/contrib,moul/contrib,lewislyou/contrib,Q-Lee/contrib,danehans/contrib,xialonglee/contrib,kskalski/contrib,ingvagabund/contrib,jcmoraisjr/k8s-contrib,timstclair/kube-contrib,jfchevrette/contrib,mikedanese/contrib,k8s-packages-power/contrib,fcvarela/contrib,marketlogicsoftware/contrib,danushkaf/contrib,k8s-packages-power/contrib,jcmoraisjr/k8s-contrib,timstclair/kube-contrib,girishkalele/contrib,endocode/contrib,xialonglee/contrib,aledbf/contrib,x13n/contrib,morganwu277/contrib,jdavis7257/contrib,girishkalele/contrib,grodrigues3/contrib,tmc/contrib,jfchevrette/kubernetes-contrib,luxas/contrib,piosz/contrib,piosz/contrib,andrew-j-price/contrib,krzyzacy/contrib,verb/contrib,rchicoli/kubernetes-contrib,Wattpad/kubernetes-contrib,pwittrock/contrib,fabioy/contrib,aknuds1/contrib,caesarxuchao/contrib,krousey/contrib,danushkaf/contrib,jojimt/contrib,krzyzacy/contrib,Arano-kai/kubernetes-contrib,pwittrock/contrib,mikedanese/contrib,aknuds1/contrib,hongchaodeng/contrib,morganwu277/contrib,eparis/contrib,aknuds1/contrib,foxish/contrib,jojimt/contrib,krousey/contrib,atosatto/kubernetes-contrib,adamschaub/contrib,jcmoraisjr/k8s-contrib,thockin/contrib,gemini-project/contrib,stephenrlouie/contrib,thockin/contrib,ixdy/kubernetes-contrib,remoe/contrib,verb/contrib,caesarxuchao/contrib