Fix :debug-console with PyQt 5.6

CHANGELOG.asciidoc

@@ -65,6 +65,7 @@ Fixed
 - Don't display quit confirmation with finished downloads
 - Fixed updating the tab index in the statusbar when opening a background tab
 - Fixed a crash when entering `:-- ` in the commandline
+- Fixed `:debug-console` with PyQt 5.6
 
 v0.6.2
 ------

qutebrowser/misc/consolewidget.py

@@ -56,7 +56,7 @@ class ConsoleLineEdit(miscwidgets.CommandLineEdit):
         self._history = cmdhistory.History(parent=self)
         self.returnPressed.connect(self.on_return_pressed)
 
-    @pyqtSlot(str)
+    @pyqtSlot()
     def on_return_pressed(self):
         """Execute the line of code which was entered."""
         self._history.stop()