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

integrations/gitea-repositories-meta/user2/utf8.git/info/exclude

@@ -0,0 +1,6 @@
+# git ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~