TT#81700 bin/check.py: fix error when --help command

> root@sp1:/usr/local/devel/kamailio-config-tests# ./bin/check.py -h
> Traceback (most recent call last):
>   File "/usr/local/devel/kamailio-config-tests/./bin/check.py", line 364, in <module>
>     args = parser.parse_args()
>   File "/usr/lib/python3.9/argparse.py", line 1830, in parse_args
>     args, argv = self.parse_known_args(args, namespace)
>   File "/usr/lib/python3.9/argparse.py", line 1863, in parse_known_args
>     namespace, args = self._parse_known_args(args, namespace)
>   File "/usr/lib/python3.9/argparse.py", line 2072, in _parse_known_args
>     start_index = consume_optional(start_index)
>   File "/usr/lib/python3.9/argparse.py", line 2012, in consume_optional
>     take_action(action, args, option_string)
>   File "/usr/lib/python3.9/argparse.py", line 1940, in take_action
>     action(self, namespace, argument_values, option_string)
>   File "/usr/lib/python3.9/argparse.py", line 1104, in __call__
>     parser.print_help()
>   File "/usr/lib/python3.9/argparse.py", line 2560, in print_help
>     self._print_message(self.format_help(), file)
>   File "/usr/lib/python3.9/argparse.py", line 2544, in format_help
>     return formatter.format_help()
>   File "/usr/lib/python3.9/argparse.py", line 295, in format_help
>     help = self._root_section.format_help()
>   File "/usr/lib/python3.9/argparse.py", line 226, in format_help
>     item_help = join([func(*args) for func, args in self.items])
>   File "/usr/lib/python3.9/argparse.py", line 226, in <listcomp>
>     item_help = join([func(*args) for func, args in self.items])
>   File "/usr/lib/python3.9/argparse.py", line 333, in _format_usage
>     action_usage = format(optionals + positionals, groups)
>   File "/usr/lib/python3.9/argparse.py", line 408, in _format_actions_usage
>     start = actions.index(group._group_actions[0])
> IndexError: list index out of range

Change-Id: I6303ab109074589e3483256eae33f43dc7c75c19

bin/check.py

@@ -357,7 +357,6 @@ def main(args):
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="generate TAP result")
-    grp = parser.add_mutually_exclusive_group()
     parser.add_argument("test_yaml_file", help="YAML file with checks")
     parser.add_argument("kam_file", help="JSON cfgt kamailio file")
     parser.add_argument("-d", "--debug", action="store_true")