Set old destination for changing connection from sorry server to real server.

Set old destination for changing connection from sorry server to real server.
Fix the following pattern (a) and (b), but not (c).
(a) 1. First connection: sorry server (over max connections)
    2. Communicate to sorry server...
    3. Some other connections done. (below max connections)
    4. Change connection: sorry -> real server
(b) 1. First connection: sorry server (force-sorry-flag is on)
    2. Communicate to sorry server...
    3. Administrator change setting (force-sorry-flag is off)
    4. Change connection: sorry -> real server
(c) 1. First connection: sorry server (no real servers)
    2. Communicate to sorry server...
    3. Administrator add real servers
    4. Change connection: sorry -> real server
       (But now connection will be closed.)