VE-1443: Added temporary, extra logging to investigate a bug

I have a suspicion that sometimes there is an attempt to execute ParsoidCacheUpdateTask task while $wgEnableVisualEditorUI is not set to true. That shouldn't be the case - this change will help to confirm if it is.
VE-1443: Addressed CR
Merge pull request #4705 from Wikia/VE-1443

VE-1443: Added temporary, extra logging to investigate a bug