Fix redirect with non-ascii branch names (#4764) (#4810)

* Fix redirect with non-ascii branch names (#4764)

* Add integration tests for non-ascii branch redirect

* Fix mysql test and coverage test

models/fixtures/repository.yml

@@ -400,3 +400,10 @@
   num_forks: 0
   num_issues: 0
   is_mirror: false
+
+-
+  id: 33
+  owner_id: 2
+  lower_name: utf8
+  name: utf8
+  is_private: false