Don't kill LatinIME if the spellchecker crashes.

If the spellchecker encounters a bug and happens to crash,
it may be sensible to avoid killing the keyboard in response.
This is a possible way to do it, which comes with the big
drawback of making bugs in the spell checker harder to find.

Change-Id: Idb26fb592b9718e1dbdadeda8fbd1a8a1d805c28