Fix issue with python script connecting before adding callbacks (#228)

Signed-off-by: amzn-mike <[email protected]>

Gems/Blast/Editor/Scripts/blast_chunk_processor.py

@@ -149,9 +149,9 @@ def on_update_manifest(args):
 try:
     import azlmbr.scene as sceneApi
     sceneJobHandler = sceneApi.ScriptBuildingNotificationBusHandler()
+    sceneJobHandler.connect()
     sceneJobHandler.add_callback('OnUpdateManifest', on_update_manifest)
     sceneJobHandler.add_callback('OnPrepareForExport', on_prepare_for_export)
-    sceneJobHandler.connect()
         
 except:
     sceneJobHandler = None