fix(common): Change Width of Update Settings Button (#17246)

Added `className='btn-link-social'` to the Update my settings button
element in Profile.jsx so that it's the same width as the other ones on
the settings page.

Closes #17230

common/app/routes/Profile/Profile.jsx

@@ -225,6 +225,7 @@ class Profile extends Component {
             block={ true }
             bsSize='lg'
             bsStyle='primary'
+            className='btn-link-social'
             >
             Update my settings
           </Button>