Another grammar fix

Author: jsa34

src/pytest_bdd/scenario.py

@@ -424,7 +424,7 @@ def _scenario() -> None:
 
                 for test_name in get_python_name_generator(scenario_name):
                     if test_name not in caller_locals:
-                        # found an unique test name
+                        # found a unique test name
                         caller_locals[test_name] = _scenario
                         break
             found = True