remove use of a static variable that was causing problems with thread safety while writing smiles
remove use of a static variable that was causing problems with thread safety while writing smiles

rvianello/rdkit,jandom/rdkit,bp-kelley/rdkit,rvianello/rdkit,rdkit/rdkit,greglandrum/rdkit,AlexanderSavelyev/rdkit,rvianello/rdkit,rvianello/rdkit,ptosco/rdkit,adalke/rdkit,rdkit/rdkit,adalke/rdkit,rdkit/rdkit,AlexanderSavelyev/rdkit,jandom/rdkit,adalke/rdkit,rvianello/rdkit,rvianello/rdkit,soerendip42/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,jandom/rdkit,ptosco/rdkit,soerendip42/rdkit,AlexanderSavelyev/rdkit,rvianello/rdkit,AlexanderSavelyev/rdkit,ptosco/rdkit,rdkit/rdkit,strets123/rdkit,soerendip42/rdkit,jandom/rdkit,rdkit/rdkit,bp-kelley/rdkit,soerendip42/rdkit,strets123/rdkit,greglandrum/rdkit,rdkit/rdkit,jandom/rdkit,bp-kelley/rdkit,jandom/rdkit,soerendip42/rdkit,AlexanderSavelyev/rdkit,AlexanderSavelyev/rdkit,adalke/rdkit,bp-kelley/rdkit,AlexanderSavelyev/rdkit,soerendip42/rdkit,ptosco/rdkit,rvianello/rdkit,bp-kelley/rdkit,strets123/rdkit,bp-kelley/rdkit,greglandrum/rdkit,strets123/rdkit,strets123/rdkit,adalke/rdkit,ptosco/rdkit,adalke/rdkit,greglandrum/rdkit,ptosco/rdkit,jandom/rdkit,greglandrum/rdkit,greglandrum/rdkit,strets123/rdkit,strets123/rdkit,ptosco/rdkit,AlexanderSavelyev/rdkit,adalke/rdkit,rdkit/rdkit,adalke/rdkit,ptosco/rdkit,soerendip42/rdkit,greglandrum/rdkit,rdkit/rdkit,AlexanderSavelyev/rdkit,greglandrum/rdkit,strets123/rdkit,jandom/rdkit,soerendip42/rdkit