BugFix: variable was not reseted in cycle and is used several times

If this variable is not reseted at the begining of cycle there are
warnings like:
Encountered duplicate id "SvgjsPolygon1067". Changed store key to
"SvgjsPolygon10676079120791982859".
And the element is duplicated
Merge pull request #28 from stochastical/master

Very tiny bug fix: variable was not reseted in cycle and is used several times