Fix for admin weight bar errors.

DMs have no limit to how much can be held in inventory due to GetWeightMax() returning NIL in dm.kod. As a result, this was setting iMaxCapacity_send to NIL and causing lots of error messages whenever the Weight Carried bar was redrawn on a DM character. On DMs, this variable is now set to 3100 which is the max inventory space currently available to a 70 might character, so the bar fills at that point now.