switch off the usage of multigen in case of hybrid sampling (i.e. when the nuisance parameters change for every toy).  In this case the pdf changes and it must be re-initialized
switch off the usage of multigen in case of hybrid sampling (i.e. when the nuisance parameters change for every toy). 
In this case the pdf changes and it must be re-initialized


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@44907 27541ba8-7e3a-0410-8455-c3a389f83636

bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT