fix regression from 1150 (#1575)
fix regression from 1150 (#1575)

verified fixes non vnet clusters outside of ci. will need to merge with another pr for clean ci pass.
Azure/acs-engine,shrutir25/acs-engine,weinong/acs-engine,shrutir25/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,PwC-ASD/acs-engine,yangl900/acs-engine,Azure/acs-engine,shrutir25/acs-engine,rjtsdl/acs-engine,anhowe/acs-engine,clementnero/acs-engine,anhowe/acs-engine,weinong/acs-engine,clementnero/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,rjtsdl/acs-engine,jackfrancis/acs-engine,rjtsdl/acs-engine,shrutir25/acs-engine,clementnero/acs-engine,rocketraman/acs-engine,rocketraman/acs-engine,yangl900/acs-engine,rocketraman/acs-engine,jackfrancis/acs-engine,PwC-ASD/acs-engine,weinong/acs-engine,anhowe/acs-engine,weinong/acs-engine,yangl900/acs-engine,jackfrancis/acs-engine,anhowe/acs-engine,yangl900/acs-engine,rjtsdl/acs-engine,anhowe/acs-engine,Azure/acs-engine,weinong/acs-engine,rjtsdl/acs-engine,PwC-ASD/acs-engine,shrutir25/acs-engine,yangl900/acs-engine,PwC-ASD/acs-engine,rocketraman/acs-engine