Use Redmine::Database.mysql? instead of a regular expression (#31555).

Patch by Pavel Rosický.


git-svn-id: http://svn.redmine.org/redmine/trunk@18256 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/20140228130325_change_changesets_comments_limit.rb

@@ -1,6 +1,6 @@
 class ChangeChangesetsCommentsLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :changesets, :comments, :text, :limit => max_size
     end