Fix for https://wikia-inc.atlassian.net/browse/MAIN-152.

The way how hook handlers was implemented was wrong - it was reading data directly from request, modyfing it with regex, and assigning to already assigned (so overwriting) property called textbox1. This way it was skipping all the hard work done in importFormData in EditPage.php.
Merge pull request #928 from Wikia/bugid-MAIN-152

Fix for https://wikia-inc.atlassian.net/browse/MAIN-152.