nvda

d6ee83ab - VirtualBuffer.prepare: do not do anything at all if the rootNVDAObject's appModule's helperLocalBindingHandle is missing.

VirtualBuffer.prepare: do not do anything at all if the rootNVDAObject's appModule's helperLocalBindingHandle is missing. There may not be any binding handle yet if NVDA was started and the document in question already had focus. All though the virtualBuffer will still not yet work, at least the user can now move focus away and back again and prepare will be tried again once the binding handle is there.