Ignore the commented lines in commit message before linting it

Ignore commented lines while checking the commit message for lines longer than 79 characters
Out of curiosity, why not use a list comprehension? Something like this:

```
long_lines = [line for line in contents if not line.startswith('#') and len(line) > 79]

if long_lines:
    print('Error: Commit messages shouldn't have lines longer than 79 chars.')
```