Update watch.php

Somehow the dbEscape($_REQUEST['mid']) returns the index enclosed in quotes. So I got a lot of erros like:

 [SQL-ERR dbFetchOne no result, statement was 'select C.*, M.* from Monitors as M left join Controls as C on (M.ControlId = C.Id ) where M.Id = ''5''']

Removing the quotes made it work for me...