Use $https_proxy environment variable, if set.
Use $https_proxy environment variable, if set.

Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

don-johnny/openconnect,pbrook/openconnect,lins05/openconnect,atyndall/openconnect,mtmiller/openconnect,pbrook/openconnect,neshema/openconnect,certik/openconnect,don-johnny/openconnect,liiir1985/openconnect,mdutton3/OpenConnect,ldx/android_external_openconnect,brandt/openconnect,atyndall/openconnect,neshema/openconnect,atyndall/openconnect,chadcatlett/openconnect,mveplus/openconnect-client,certik/openconnect,lins05/openconnect,mveplus/openconnect-client,brandt/openconnect,liiir1985/openconnect,mdutton3/OpenConnect,mveplus/openconnect-client,brandt/openconnect,liiir1985/openconnect,mtmiller/openconnect,lins05/openconnect,matlockx/openconnect,chadcatlett/openconnect,mtmiller/openconnect,matlockx/openconnect,cernekee/openconnect,nmav/openconnect-mine,nmav/openconnect-mine,neshema/openconnect,nmav/openconnect-mine,cernekee/openconnect,ldx/android_external_openconnect,mtmiller/openconnect,don-johnny/openconnect,mveplus/openconnect-client,neshema/openconnect,nmav/openconnect-mine,matlockx/openconnect,sihde/openconnect,chadcatlett/openconnect,liiir1985/openconnect,cernekee/openconnect,mdutton3/OpenConnect,brandt/openconnect,cernekee/openconnect,don-johnny/openconnect,sihde/openconnect,atyndall/openconnect,chadcatlett/openconnect,certik/openconnect,sihde/openconnect,matlockx/openconnect,lins05/openconnect