Actually check for duplicate extensions
Actually check for duplicate extensions

letsencrypt/boulder,bmw/boulder,jfrazelle/boulder,benileo/boulder,ZCloud-Firstserver/boulder,jfrazelle/boulder,jsha/boulder,jfrazelle/boulder,benileo/boulder,sophie-h/boulder,sophie-h/boulder,ibukanov/boulder,bmw/boulder,jsha/boulder,mehmooda/boulder,jsha/boulder,letsencrypt/boulder,mehmooda/boulder,benileo/boulder,ZCloud-Firstserver/boulder,mehmooda/boulder,jcjones/boulder,ibukanov/boulder,bmw/boulder,lucasallan/boulder,patf/boulder,lucasallan/boulder,benileo/boulder,ZCloud-Firstserver/boulder,jcjones/boulder,patf/boulder,jcjones/boulder,jfrazelle/boulder,mehmooda/boulder,lucasallan/boulder,ibukanov/boulder,ZCloud-Firstserver/boulder,sophie-h/boulder,jcjones/boulder,patf/boulder,patf/boulder,letsencrypt/boulder