[ci skip] Update to AppVeyor config.
[ci skip] Update to AppVeyor config.

BentSm/povray,POV-Ray/povray,LeForgeron/povray,c-lipka/povray,eblanca/povray,LeForgeron/povray,wfpokorny/povray,LeForgeron/povray,wfpokorny/povray,LeForgeron/povray,POV-Ray/povray,LeForgeron/povray,LeForgeron/povray,POV-Ray/povray,wfpokorny/povray,wfpokorny/povray,c-lipka/povray,eblanca/povray,LeForgeron/povray,c-lipka/povray,LeForgeron/povray,eblanca/povray,wfpokorny/povray,wfpokorny/povray,BentSm/povray,BentSm/povray,POV-Ray/povray,eblanca/povray,c-lipka/povray,POV-Ray/povray,POV-Ray/povray,BentSm/povray,POV-Ray/povray,wfpokorny/povray