Use Damageable#damage(double) instead of Damageable#setHealth(double)

Using Float.MAX_VALUE as that is what `/minecraft:kill` uses

Fixes EssentialsX#5842

Author: zaoom

Essentials/src/main/java/com/earth2me/essentials/commands/Commandkill.java

@@ -34,7 +34,7 @@ protected void updatePlayer(final Server server, final CommandSource sender, fin
             return;
         }
         ede.getEntity().setLastDamageCause(ede);
-        matchPlayer.setHealth(0);
+        matchPlayer.damage(Float.MAX_VALUE);
         sender.sendTl("kill", matchPlayer.getDisplayName());
     }