Weaken the recursion guard on RequestContext::getLanguage()

Just log and soldier on, since for some reason we are seeing a lot of
these exceptions at the moment, with multiple root causes. Based on Matt
Walker's I49dbc2d7. Updates Idc11b547. See bug 44754.

Change-Id: I2e8c062741c1b2ec2acd68dc76d3fb6efb113571