[PATCH] remove superflous error message about wiki_namespace

[anonymous]

Upgrading to the current SVN trunk, I noticed today error messages

Trac[model] ERROR: DatabaseError: no such table: wiki_namespace

in my logs. svn blame model.py points to [10384], where that logging was added.

As far as I can see, that wiki_namespace table is not supposed to exist, and it surely does not exist in my setup. The _need_migration function's try block attempts to access the table for the sole purpose to note its existance - with the except: path being the expected outcome on newer versions not needing migration. Or, at least, that's how the whole thing looks to me...

Appended patch just removes that error message output.