error message normally is provided, when incorrect params are entered by user
for example latest.php?&form_refresh=1&groupid=XXX&hostid=XXX requires 2 params
when entering incorrect integers for both -groupid and hostid, there should be error message produced
so user is aware that such group or host doesn't exist

hosts.php?form=update&hostid=50001&groupid=4440 works correctly,
presenting user with an error message that such object (groupid) doesnt exist