Fix so users with apostrophes won't cause 500 errors.
It's possible to get a user with an apostrophe due to active directory.

This change allows the regex to recognize these users.

I created a user with an apostrophe in the name and went through the steps to reproduce the problem (going to users page, as well as trying to assign the apostrophe user to a review). 500 errors were no longer thrown after my changes.