Adding new ap-southeast-5 AWS region

(cherry picked from commit ad5ca2443f053dd0ad686852a93f4964a098369a)

Source commit: fa83abcda41939c3c493b57fcda18532a3a87f36

source/forms/SiteAdvanced.dfm

@@ -1073,6 +1073,7 @@ object SiteAdvancedDialog: TSiteAdvancedDialog
               'ap-southeast-2'
               'ap-southeast-3'
               'ap-southeast-4'
+              'ap-southeast-5'
               'ca-central-1'
               'ca-west-1'
               'cn-north-1'