getclient: Fix sourced env variables
getclient: Fix sourced env variables

* Update to use the sourced environemental variables.
* Add switch for not using default gateway.

chadoe/docker-openvpn,mouyigang/docker-openvpn,dx9/docker-openvpn,hanjaelee/docker-openvpn,caervs/docker-openvpn,ypid/docker-openvpn,elie195/docker-openvpn,rdev02/docker-openvpn,myplacedk/docker-openvpn,alessandro-aglietti/docker-openvpn,slamont/docker-openvpn,pushrax/docker-openvpn,StefanGuelland/docker-openvpn,shanonvl/docker-openvpn,morcavon/docker-openvpn,richnologies/docker-openvpn,SamuelMoraesF/Docker-OpenVPN,hjnijlunsing/docker-openvpn-armhf,jeffcao/docker-openvpn,gl-sergei/docker-openvpn,neingeist/docker-openvpn,kylemanna/docker-openvpn,GuiMouth/docker-openvpn,wernerb/docker-openvpn,csakoda/docker-openvpn,jvassev/docker-openvpn