Usage: servergroupdelperm sgid={groupID} permid={permID}|permid={permID}
       servergroupdelperm sgid={groupID} permsid={permName}

Removes a set of specified permissions from the server group specified with 
sgid. Multiple permissions can be removed at once. A permission can be 
specified by permid or permsid.

Examples:
   servergroupdelperm sgid=16 permid=8470|permid=8475
   error id=0 msg=ok

   servergroupdelperm sgid=16 permsid=i_channel_join_power
   error id=0 msg=ok