nvda

afc5dd1b - Fix exceptions when IAccessibleApplication.toolkitVersion for a Mozilla accessible returns None.

Fix exceptions when IAccessibleApplication.toolkitVersion for a Mozilla accessible returns None. This doesn't happen for Mozilla software, but it apparently can for third party software which embeds Gecko as reported here: https://www.freelists.org/post/nvda-addons/Failure-in-recognizing-Gecko-version