fix wait boot_command regex.
fix wait boot_command regex.

Resolves #4268

pecigonzalo/packer,dave2/packer,ricardclau/packer,c22/packer,tb3088/packer,dayglojesus/packer,rnaveiras/packer,tas50/packer,tsmolka/packer,grubernaut/packer,dave2/packer,mwhooker/packer,youhong316/packer,boumenot/packer,pvandervelde/packer,ricardclau/packer,rnaveiras/packer,taliesins/packer,taliesins/packer,tas50/packer,ChrisLundquist/packer,dayglojesus/packer,paulmey/packer,sean-/packer,routelastresort/packer,mafrosis/packer,smaato/packer,bryson/packer,tsmolka/packer,bryson/packer,mwhooker/packer,routelastresort/packer,smaato/packer,KohlsTechnology/packer,mwhooker/packer,pieter-lazzaro/packer,tas50/packer,life360/packer,mitchellh/packer,arizvisa/packer,atlassian/packer,hashicorp/packer,legal90/packer,tb3088/packer,bryson/packer,KohlsTechnology/packer,paulmey/packer,pvanbuijtene/packer,ChrisLundquist/packer,tsmolka/packer,dayglojesus/packer,legal90/packer,life360/packer,youhong316/packer,quantang/packer,youhong316/packer,life360/packer,paulmey/packer,jimmythedog/packer,rickard-von-essen/packer,zhuzhih2017/packer,atlassian/packer,jimmythedog/packer,mwhooker/packer,atlassian/packer,atlassian/packer,mkuzmin/packer,p1-nico/packer,mafrosis/packer,jimmythedog/packer,tsmolka/packer,atlassian/packer,zhuzhih2017/packer,dave2/packer,paulmey/packer,ChrisLundquist/packer,life360/packer,rickard-von-essen/packer,arizvisa/packer,pecigonzalo/packer,routelastresort/packer,legal90/packer,taliesins/packer,zhuzhih2017/packer,routelastresort/packer,youhong316/packer,c22/packer,bryson/packer,jen20/packer,pieter-lazzaro/packer,rnaveiras/packer,mkuzmin/packer,tb3088/packer,mkuzmin/packer,smaato/packer,youhong316/packer,pecigonzalo/packer,quantang/packer,KohlsTechnology/packer,sean-/packer,timsutton/packer,dayglojesus/packer,mitchellh/packer,p1-nico/packer,jen20/packer,markpeek/packer,jen20/packer,boumenot/packer,quantang/packer,taliesins/packer,hashicorp/packer,tas50/packer,grubernaut/packer,pvanbuijtene/packer,pvandervelde/packer,c22/packer,zhuzhih2017/packer,sean-/packer,hashicorp/packer,boumenot/packer,quantang/packer,sneal/packer,pvanbuijtene/packer,routelastresort/packer,tas50/packer,sean-/packer,tas50/packer,ricardclau/packer,c22/packer,sean-/packer,tb3088/packer,ricardclau/packer,pieter-lazzaro/packer,sneal/packer,mitchellh/packer,p1-nico/packer,youhong316/packer,p1-nico/packer,dave2/packer,paulmey/packer,ricardclau/packer,pvandervelde/packer,zhuzhih2017/packer,rnaveiras/packer,bryson/packer,sean-/packer,pieter-lazzaro/packer,mkuzmin/packer,jen20/packer,ChrisLundquist/packer,markpeek/packer,jen20/packer,pvandervelde/packer,arizvisa/packer,dave2/packer,rnaveiras/packer,tb3088/packer,timsutton/packer,tsmolka/packer,smaato/packer,tsmolka/packer,timsutton/packer,legal90/packer,rickard-von-essen/packer,sneal/packer,quantang/packer,p1-nico/packer,pvandervelde/packer,rnaveiras/packer,grubernaut/packer,boumenot/packer,markpeek/packer,arizvisa/packer,mkuzmin/packer,pvanbuijtene/packer,sneal/packer,mafrosis/packer,mafrosis/packer,bryson/packer,smaato/packer,ChrisLundquist/packer,timsutton/packer,KohlsTechnology/packer,sneal/packer,arizvisa/packer,pvandervelde/packer,markpeek/packer,tb3088/packer,mitchellh/packer,taliesins/packer,pieter-lazzaro/packer,rickard-von-essen/packer,jimmythedog/packer,legal90/packer,taliesins/packer,pecigonzalo/packer,zhuzhih2017/packer,mkuzmin/packer,grubernaut/packer,mitchellh/packer,KohlsTechnology/packer,jen20/packer,markpeek/packer,life360/packer,mwhooker/packer,boumenot/packer,markpeek/packer,timsutton/packer,ChrisLundquist/packer,grubernaut/packer,p1-nico/packer,smaato/packer,timsutton/packer,grubernaut/packer,mafrosis/packer,dayglojesus/packer,atlassian/packer,jimmythedog/packer,pvanbuijtene/packer,pieter-lazzaro/packer,dave2/packer,KohlsTechnology/packer,c22/packer,c22/packer,arizvisa/packer,ricardclau/packer,hashicorp/packer,rickard-von-essen/packer,paulmey/packer