expires.conf: add missing .htc file type
expires.conf: add missing .htc file type

eric-seekas/server-configs-nginx,rafwlaz/server-configs-nginx,AgtLucas/server-configs-nginx,yggsoft/server-configs-nginx,jlien-calwater/server-configs-nginx,iDTLabssl/server-configs-nginx,damnfine/server-configs-nginx,tomtarrot/server-configs-nginx,Qoto/server-configs-nginx,szepeviktor/server-configs-nginx,k0nsl/server-configs-nginx,heivin/server-configs-nginx,diegocastro/server-configs-nginx,lifecom/server-configs-nginx,blmlove409/server-configs-nginx,unixboy/server-configs-nginx,yshaojie/server-configs-nginx,chranderson/server-configs-nginx,dliggat/sample-nginx-config,Olvikolvi/server-configs-nginx,njmube/server-configs-nginx,bond-agency/server-configs-nginx,georgemarselis/server-configs-nginx,TheBookPeople/server-configs-nginx,cxnam/server-configs-nginx,susaing/server-configs-nginx,kane-c/server-configs-nginx,dolymood/server-configs-nginx