Description of problem:

When the keystone crontab value contains `keystone-manage token_flush`, but it's commented out, the validation is still passing.

Version-Release number of selected component (if applicable):


How reproducible:

always

Steps to Reproduce:
1. Run: `sudo crontab -e -u keystone`
2. Find the line with `keystone-manage token_flush` or add this if it doesn't exist: `1 0 * * * keystone-manage token_flush >>/dev/null 2>&1`
3. Comment the token_flush line out

Actual results:

The validation passes.


Expected results:

The validation should fail as the value is commented out.


Additional info: