don't clobber existing to_parties list
don't clobber existing to_parties list

this was screwing up the director[0],director[1] syntax

resolves https://github.com/legalese/legalese.com/issues/239

legalese/legalese-google-app,legalese/legalese-google-app,legalese/legalese-google-app,legalese/legalese-google-app,legalese-io/legalese-google-app,legalese/legalese-google-app