htmlArea RTE: Initialization fails in presence of Firefox extension Ant.com Toolbar 1.3
Firefox extension Ant.com Toolbar 1.3 modifies the browser useragent string to which it appends "Ant.com Toolbar 1.3".
RTE erroneously identifies the browser as Mozilla version 1.3 for which initialization is different. Initialization then fails to complete.
(issue imported from #M10656)