[ticket/12695] Add viewtopic language file for parse_attachments in mcp_post

PHPBB3-12695
Merge pull request #2722 from marc1706/ticket/12695

[ticket/12695] Add viewtopic language file for parse_attachments in mcp_...

* marc1706/ticket/12695:
  [ticket/12695] Add viewtopic language file for parse_attachments in mcp_post