wxGUI: fix 'clear output'

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@40198 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/goutput.py

@@ -515,7 +515,9 @@ class GMConsole(wx.SplitterWindow):
 
     def ClearHistory(self, event):
         """!Clear history of commands"""
+        self.cmd_output.SetReadOnly(False)
         self.cmd_output.ClearAll()
+        self.cmd_output.SetReadOnly(True)
         self.console_progressbar.SetValue(0)
 
     def SaveHistory(self, event):