Adding new ap-southeast-6 AWS region

(cherry picked from commit a617de9743bbd4bc125cfbe26052497710974b82)

Source commit: d16cc7c756585a9c5ec2310934855bc6c8c23de7

source/forms/SiteAdvanced.dfm

@@ -1086,6 +1086,7 @@ object SiteAdvancedDialog: TSiteAdvancedDialog
               'ap-southeast-3'
               'ap-southeast-4'
               'ap-southeast-5'
+              'ap-southeast-6'
               'ap-southeast-7'
               'ca-central-1'
               'ca-west-1'