Adding new ap-southeast-3 AWS region

(cherry picked from commit 9bd1d563ca9622faaa408eb57378f0ba5f7bfee9)

Source commit: faa8f999a14e996bfcfb615db114f3df8cfbdf55

source/forms/SiteAdvanced.dfm

@@ -1059,6 +1059,7 @@ object SiteAdvancedDialog: TSiteAdvancedDialog
               'ap-south-1'
               'ap-southeast-1'
               'ap-southeast-2'
+              'ap-southeast-3'
               'ca-central-1'
               'cn-north-1'
               'cn-northwest-1'