...because SwBreakIt::_Delete clears g_pBreakIt but SwTxtNode::GetLang (called
indirectly from GrammarCheckingIterator::DequeueAndCheck) expects it to be non-
null.  That caused CppunitTest_libreofficekit_tiledrendering to occasionally
fail.

Change-Id: Ia350e2531067dd8308dfa20567cc00e1140f764c