Changed warning text

Author: kmvanbrunt

cmd2/cmd2.py

@@ -3247,7 +3247,7 @@ def py_run(filename: str):
                 expanded_filename = os.path.expanduser(filename)
 
                 if not expanded_filename.endswith('.py'):
-                    self.pwarning("'{}' does not appear to be a Python file".format(expanded_filename))
+                    self.pwarning("'{}' does not have a .py extension".format(expanded_filename))
                     selection = self.select('Yes No', 'Continue to try to run it as a Python script? ')
                     if selection != 'Yes':
                         return

tests/test_run_pyscript.py

@@ -50,7 +50,7 @@ def test_run_pyscript_with_non_python_file(base_app, request):
     test_dir = os.path.dirname(request.module.__file__)
     filename = os.path.join(test_dir, 'scripts', 'help.txt')
     out, err = run_cmd(base_app, 'run_pyscript {}'.format(filename))
-    assert "does not appear to be a Python file" in err[0]
+    assert "does not have a .py extension" in err[0]
 
 def test_run_pyscript_with_exception(base_app, request):
     test_dir = os.path.dirname(request.module.__file__)