CLOUDSTACK-4702: UI > Network menu > Add Guest Network dialog > UI shouldn't pass null zoneid to listnetworkofferings API when zone dropdown is empty (i.e. when no advanced zone exists).
CLOUDSTACK-4702: UI > Network menu > Add Guest Network dialog > UI shouldn't pass null zoneid to listnetworkofferings API when zone dropdown is empty (i.e. when no advanced zone exists).

mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver