Corrected its values

I placed the wrong values for this spell.
Merge pull request #490 from raymondtfr/patch-3

Corrected its values
Update potions.lua

Updated potions healing so it may look like rl tibia, and moreover to better work in conjunction with the recent changes I've made to the spells, hence the critical need of updating potions healing damages...
Merge pull request #494 from raymondtfr/patch-3

Update potions.lua
Merge pull request #492 from dalkon/master

Fix #376