Updated tk-multi-loader2 to v1.20.3

Release notes: https://github.com/shotgunsoftware/tk-multi-loader2/wiki/Release-Notes#v1203

Author: Toolkitty

env/includes/common/apps.yml

@@ -45,7 +45,7 @@ common.apps.tk-multi-publish2.location:
 common.apps.tk-multi-loader2.location:
   type: app_store
   name: tk-multi-loader2
-  version: v1.20.2
+  version: v1.20.3
 
 common.apps.tk-multi-shotgunpanel.location:
   type: app_store