Default to argv=None for commands

qutebrowser/commands.py

@@ -47,7 +47,7 @@ class Command(QObject):
                       (self.nargs == '+' and len(argv) < 1)):
             raise TypeError("Invalid argument count!")
 
-    def run(self, argv):
+    def run(self, argv=None):
         if not self.signal:
             raise NotImplementedError
         self.signal.emit()

qutebrowser/keys.py

@@ -21,4 +21,4 @@ class KeyParser(QObject):
         if cmd.nargs and cmd.nargs != 0:
             self.set_cmd_text.emit(':{} '.format(cmd.name))
         else:
-            cmd.run([])
+            cmd.run()