Fixed bugreport:7159 where cooking formula and creation effect is not working properly.
Fixed bugreport:7129 where GN_MANDRAGORA is not working with other skills.

git-svn-id: https://rathena.svn.sourceforge.net/svnroot/rathena/trunk@17093 54d463be-8e91-2dee-dedb-b68131a5f0ec