Tell early parser not to add help

cura_app.py

@@ -9,7 +9,8 @@ import sys
 
 from UM.Platform import Platform
 
-parser = argparse.ArgumentParser(prog = "cura")
+parser = argparse.ArgumentParser(prog = "cura",
+                                 add_help = False)
 parser.add_argument('--debug',
                     action='store_true',
                     default = False,