Merge branch 'fix/import_data-migration' into 'master'

Fix migration corrupting import data for old version upgrades

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19073

Not a fan of changing old migrations but this will prevent issues from upgrading GitLab version 8.6 or older to 8.10

More details of the issue on https://gitlab.com/gitlab-org/gitlab-ce/issues/19073#note_13190450

See merge request !5358

CHANGELOG

@@ -135,6 +135,7 @@ v 8.10.0 (unreleased)
   - Allow bulk (un)subscription from issues in issue index
   - Fix MR diff encoding issues exporting GitLab projects
   - Export and import avatar as part of project import/export
+  - Fix migration corrupting import data for old version upgrades
 v 8.9.6
   - Fix importing of events under notes for GitLab projects. !5154

db/migrate/20160302152808_remove_wrong_import_url_from_projects.rb

@@ -7,7 +7,13 @@ class RemoveWrongImportUrlFromProjects < ActiveRecord::Migration
   class ProjectImportDataFake
     extend AttrEncrypted
     attr_accessor :credentials
-    attr_encrypted :credentials, key: Gitlab::Application.secrets.db_key_base, marshal: true, encode: true, :mode => :per_attribute_iv_and_salt
+    attr_encrypted :credentials,
+                   key: Gitlab::Application.secrets.db_key_base,
+                   marshal: true,
+                   encode: true,
+                   :mode => :per_attribute_iv_and_salt,
+                   insecure_mode: true,
+                   algorithm: 'aes-256-cbc'
   end
   def up