Clear end2end test data again after initializing

If we don't do this, earlier tests can affect later ones when e.g. using "...
should not be logged", as we don't really wait until a test has been fully
finished.

tests/end2end/fixtures/quteprocess.py

@@ -527,6 +527,7 @@ class QuteProc(testprocess.Process):
         super().before_test()
         self.send_cmd(':config-clear')
         self._init_settings()
+        self.clear_data()
 
     def _init_settings(self):
         """Adjust some qutebrowser settings after starting."""