DBManager: db_url_info->local needs to be casted to int.

Fixes issues with dump() and external databases.

Thanks to Arne Goedeke <el@laramies.com> for the report and patch.

Fixes [bug 7386].
Merge branch 'patches/bug7386' into 5.4

* patches/bug7386:
  DBManager: db_url_info->local needs to be casted to int.