Bugfix: load widget just if it is not already loaded.

I ran into this issue when I was trying to set file validation to all widgets in a page. As I was using widget in standalone and plugin ways, here's what happened:

# Standalone plugin was loaded
# File validation was set
# CKEditor plugin reloaded widget with delay, resetting file validation

So we need to check for a loaded widget instance before load it blindly, right?


Hope it helps!