bugfix: unknown tag attributes should not be reported as 'internal server errors'.
bugfix: unknown tag attributes should not be reported as 'internal server errors'.

pavlobaron/disco_playground,oldmantaiter/disco,beni55/disco,simudream/disco,simudream/disco,seabirdzh/disco,seabirdzh/disco,seabirdzh/disco,scrapinghub/disco,pavlobaron/disco_playground,oldmantaiter/disco,mwilliams3/disco,ErikDubbelboer/disco,scrapinghub/disco,pavlobaron/disco_playground,pombredanne/disco,beni55/disco,discoproject/disco,ErikDubbelboer/disco,simudream/disco,discoproject/disco,pavlobaron/disco_playground,discoproject/disco,pombredanne/disco,mozilla/disco,oldmantaiter/disco,simudream/disco,pombredanne/disco,mwilliams3/disco,ErikDubbelboer/disco,oldmantaiter/disco,pombredanne/disco,oldmantaiter/disco,ktkt2009/disco,ErikDubbelboer/disco,discoproject/disco,ktkt2009/disco,pooya/disco,scrapinghub/disco,pombredanne/disco,beni55/disco,simudream/disco,mwilliams3/disco,pooya/disco,mozilla/disco,mwilliams3/disco,scrapinghub/disco,ErikDubbelboer/disco,beni55/disco,seabirdzh/disco,pooya/disco,discoproject/disco,beni55/disco,mwilliams3/disco,mozilla/disco,seabirdzh/disco,pooya/disco,ktkt2009/disco,mozilla/disco,ktkt2009/disco,ktkt2009/disco