Merge pull request #8462 from crdlc/bug-847635

Bug 847635 - [B2G][Contacts] Grayed out Facebook fields become editable ...(cherry picked from commit fdf593004911cf5ca35e57f9337da023c10ef55d)
(cherry picked from commit 6d4d7778f68810337462b6a814c6ec5c12ce968e)