[For 1.8] MyConversations: a conversation plugin for MyBB

[Laird]

I believe I fixed it by adding a line at 1248 to define it.
$cnv_unread_convmsgs = '';

Is it that simple? Define a variable? That variable only appears within the function, so definition stays within the function.

The fix turned out to be slightly different - to change line 1276 from:

			$mybb->user['cnv_unread_msg_str'] = $cnv_unread_convmsgs;

to:

			$mybb->user['cnv_unread_msg_str'] = $lang->cnv_avail_to_members_only;

I'd recently added that language key for that purpose, but forgotten to use it.