httppeer: make __del__ access to self.urlopener more safe Some errors could in some cases show unfortunate scary and confusing warnings from the httppeer delstructors: abort: nodename nor servname provided, or not known Exception AttributeError: "'httpspeer' object has no attribute 'urlopener'" in <bound method httpspeer.__del__ of <mercurial.httppeer.httpspeer object at 0x106e1f5d0>> ignored``` To mute that, take 7b15dd9125b3 to the next level and use getattr in __del__.