title: Flask + Flask-Security + Babel not working
body: <p>I have setup with Flask + Babel + Flask Security.
  Created all translation like this:</p>
  
  <ul>
  <li>root
  
  <ul>
  <li>main.py</li>
  <li>translations
  
  <ul>
  <li>ru
  
  <ul>
  <li>LC_MESSAGES
  
  <ul>
  <li>messages.mo</li>
  <li>messages.po</li>
  </ul></li>
  </ul></li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>In main.py there is part to setup language which executes:</p>
  
  <pre><code>@babel.localeselector
  def get_locale():
      user = getattr(g, 'user', None)
      if user is not None:
          print("User locale {}".format(user.locale))
          return user.locale
      # I put here constant to test
      return 'ru'
  </code></pre>
  
  <p>But <a href="http://localhost/login" rel="nofollow noreferrer">http://localhost/login</a> stayed untranslated. Can you please advice where else to dig? No errors in logs even with <strong>Debug = True</strong></p>