Description:
------------
When using GSSAPI (SASL) authentication w/ cyrus, strace and kerberos credentials indicate that authentication is successful, but the cyrus_authenticate() function reports that authentication fails.

Reproduce code:
---------------
$connection = cyrus_connect( 'cyrus.example.com', 143 );
if ( cyrus_authenticate( $connection, 'GSSAPI', 'imap', 'juser', 0, 1000 )){
    print( "i authenticated<br>" );
} else {
    print( "i couldn't authenticate<br>" );
}


Expected result:
----------------
cyrus_authenticate() should return TRUE

Actual result:
--------------
Strace show's that the user's authenticated..

11200 write(4, "1 AUTHENTICATE GSSAPI\r\n", 23) = 23
11200 select(5, [4], [], NULL, NULL)    = 1 (in [4])
11200 read(4, "* OK cyrus.example.com Cyrus IMAP4 Murder v2.2.8 server ready\r\n", 4096) = 73
11200 select(5, [4], [], NULL, NULL)    = 1 (in [4])
11200 read(4, "+ \r\n", 4096)           = 4
...bunch of kerberos stuff....
11200 read(4, "1 OK Success (privacy protection)\r\n", 4096) = 35

but the value returned by cyrus_authenticate() is FALSE