Camera purchases do not properly check points balance.

Recently discovered that the camera purchase event does not properly check the user's balance, and will decrement below zero if necessary.

i.e. User has 0 duckets, purchasing camera photos costs 25 duckets, the user now has -25 duckets.

Not sure if the client tries to do this check itself, I haven't tried it manually, but sending the packet manually results in this behavior. Tested and confirmed issue on Arcturus 1.15.0.