move return back, change associated_obj to associated

There aren't any changes to associated before we try to create the
Relationship, so I think it's ok to do the early return earlier.

We create the relationship between associated and target, not associated_obj,
so we should check it instead.

app/models/concerns/smooch_messages.rb

@@ -430,6 +430,7 @@ def smooch_post_save_message_actions(message, associated, app_id, author, reques
     end
 
     def smooch_relate_items_for_same_message(message, associated, app_id, author, request_type, associated_obj)
+      return unless associated.is_a?(ProjectMedia)
       if !message['caption'].blank?
         # Check if message contains caption then create an item and force relationship
         self.relate_item_and_text(message, associated, app_id, author, request_type, associated_obj, Relationship.confirmed_type)
@@ -456,7 +457,6 @@ def relate_item_and_text(message, associated, app_id, author, request_type, asso
       target = self.create_project_media_from_message(message)
       unless target.nil?
         smooch_post_save_message_actions(message, target, app_id, author, request_type, associated_obj)
-        return unless associated_obj.is_a?(ProjectMedia)
         Relationship.create_unless_exists(associated.id, target.id, relationship_type)
       end
     end