Tribute Remove events fire multiple times when falling out of the world

[jcxldn]

Example (tested on #28):

§eFarewell, jcxLDN
 jcxLDN has died.
VoxelSniper has been re-enabled for you!
WorldEdit has been re-enabled for you!
Zero players are left. This shouldn't happen. Tell the devs about this!
§eFarewell, jcxLDN
jcxLDN has died.
VoxelSniper has been re-enabled for you!
WorldEdit has been re-enabled for you!
§ejcxLDN fell into a bottomless pit
 jcxLDN has died.
VoxelSniper has been re-enabled for you!
WorldEdit has been re-enabled for you!