mozilla: ensure the scintilla plugin is loaded synchronously
* this keeps the plugin loading the same as it was in earlier versions of Komodo

(integrated from komodo (trunk) change 84926 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@14343 b87d16e7-d29f-4ee1-b5ec-817d645d335f