Remove `permanent` from `redirect_routes`

This removes the column that was added in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15670 since we
will no longer be allowing _permanent_ redirects

db/post_migrate/20180305100050_remove_permanent_from_redirect_routes.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RemovePermanentFromRedirectRoutes < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  disable_ddl_transaction!
+
+  INDEX_NAME_PERM = "index_redirect_routes_on_path_text_pattern_ops_where_permanent"
+  INDEX_NAME_TEMP = "index_redirect_routes_on_path_text_pattern_ops_where_temporary"
+
+  def up
+    # These indexes were created on Postgres only in:
+    # ReworkRedirectRoutesIndexes:
+    # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/16211
+    if Gitlab::Database.postgresql?
+      disable_statement_timeout
+
+      execute "DROP INDEX CONCURRENTLY IF EXISTS #{INDEX_NAME_PERM};"
+      execute "DROP INDEX CONCURRENTLY IF EXISTS #{INDEX_NAME_TEMP};"
+    end
+
+    remove_column(:redirect_routes, :permanent)
+  end
+
+  def down
+    add_column(:redirect_routes, :permanent, :boolean)
+
+    if Gitlab::Database.postgresql?
+      disable_statement_timeout
+
+      execute("CREATE INDEX CONCURRENTLY #{INDEX_NAME_PERM} ON redirect_routes (lower(path) varchar_pattern_ops) where (permanent);")
+      execute("CREATE INDEX CONCURRENTLY #{INDEX_NAME_TEMP} ON redirect_routes (lower(path) varchar_pattern_ops) where (not permanent or permanent is null) ;")
+    end
+  end
+end

db/schema.rb

@@ -1605,7 +1605,6 @@ ActiveRecord::Schema.define(version: 20180327101207) do
     t.string "path", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.boolean "permanent"
   end
 
   add_index "redirect_routes", ["path"], name: "index_redirect_routes_on_path", unique: true, using: :btree