Another .one -> .find_one

Same idea as in the previous commit.
Joar caught this one.

To reproduce
1. Create a user with an all-decimal ObjectId in mongo
2. Login using that user, while mongodb is enabled.
3. Switch instance to sql.
4. Restart.
5. Refresh any page.

This will error, because no user with that object id exists
any more.

While around, improved logging.

mediagoblin/tools/request.py

@@ -14,8 +14,12 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import logging
 from mediagoblin.db.util import ObjectId, InvalidId
 
+_log = logging.getLogger(__name__)
+
+
 def setup_user_in_request(request):
     """
     Examine a request and tack on a request.user parameter if that's
@@ -30,12 +34,12 @@ def setup_user_in_request(request):
     except InvalidId:
         user = None
     else:
-        user = request.db.User.one({'_id': oid})
+        user = request.db.User.find_one({'_id': oid})
 
     if not user:
         # Something's wrong... this user doesn't exist?  Invalidate
         # this session.
-        print "Killing session for %r" % request.session['user_id']
+        _log.warn("Killing session for user id %r", request.session['user_id'])
         request.session.invalidate()
 
     request.user = user