Added catch of SQLiteException when updating screenshot

Error found when running Monkey test. User probably tries
to add a bookmark and directly after deleting it. The method
updateScreenshot is running an AsyncTask and gets an Exception
from the database when the bookmark does not exist. The deletion
of the bookmark runs in another thread.

Change-Id: I63bb954419f60fb5106c1a6597692b6bac925714
1 file changed