Fix for making privatemsg settings show up in just one user profile edit category

As the module is now, the settings for whether to allow all users or only your friends to send you private messages, will show up under all tabs (categories) when editing user settings. It should show up only under the "account" category.

this is fixed by changing this line (in user_relationships_ui.module hook_user under the 'form' op) from:

    if (module_exists('privatemsg')) { //check if privatemsg is installed

to this:

    if (module_exists('privatemsg') && $category == 'account') { //check if privatemsg is installed