Absorption effect above level 4 is always the same as level 4

Steps to Reproduce:

1. Use the /effect command with absorption and add amplifier 4  
2. clear the effects and add the same again but add amplifier 5 instead 
3. you will notice the absorption hearts still the same amount of the amplifier 4 

Observed Results:
The command gives you the same amount of absorption hearts when the amplifier is 5 or higher

Expected Results:
The command should gives more absorption hearts when the amplifier is 5 or higher