[imp] Search.php changed -- breaks filter on Spam Header

[Dan Wilson]

Since the change to imp/lib/Search.php on 11 Feb, my filter for the X-Spam-
Status header is broken.  All other filters still work fine.

I went in and looked around... it looks like there is a variable that is 
$mailbox and it should be $mbox, but there is an additional problem with the 
Illegal offset on line 289.  I'm not sure how to fix that one.

Here are the errors I get:

Notice: Undefined variable: mailbox 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 278

Notice: Undefined variable: mailbox 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 279

Notice: Undefined variable: mailbox 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 289

Warning: Illegal offset type 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 289

Notice: Undefined variable: mailbox 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 290

Warning: Illegal offset type 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 290

Notice: Undefined variable: mailbox 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 292

Warning: Illegal offset type 
in /home/dan/public_html/dev_horde/imp/lib/Search.php on line 292

-Dan