Revert "Merge pull request #1940 from Wikia/rename-photo-to-image"

This reverts commit f1bf5769f48b1bcb4001579601d737d5423f0fa4, reversing
changes made to 76c62e4ef03a975f7eb2787d6f54dba67555c4a0.

Conflicts:
	extensions/VisualEditor/wikia/modules/ve/ui/dialogs/ve.ui.WikiaMediaInsertDialog.js