configtool: add check for wxPython 4

configtool/gui.py

@@ -3,6 +3,10 @@ import sys
 import time
 try:
   import wx
+  if wx.__version__[0] < 4:
+    print("Configtool needs wxPython 4.x. Please check https://wxpython.org/pages/downloads/.")
+    time.sleep(10)
+    sys.exit(-1)
 except:
   print("ImportError: No module named wx\n\n"
         "wxPython is not installed. This program requires wxPython to run.\n"