Fix gitignore for core/vendor
Fix gitignore for core/vendor

* es6-promise and davclient.js

pollopolea/core,endsguy/server,pixelipo/server,sharidas/core,endsguy/server,owncloud/core,bluelml/core,pollopolea/core,jbicha/server,cernbox/core,IljaN/core,pixelipo/server,andreas-p/nextcloud-server,pollopolea/core,Ardinis/server,michaelletzgus/nextcloud-server,Ardinis/server,whitekiba/server,andreas-p/nextcloud-server,cernbox/core,pmattern/server,sharidas/core,Ardinis/server,bluelml/core,pmattern/server,bluelml/core,jbicha/server,nextcloud/server,nextcloud/server,xx621998xx/server,jbicha/server,bluelml/core,xx621998xx/server,whitekiba/server,whitekiba/server,andreas-p/nextcloud-server,owncloud/core,pixelipo/server,pixelipo/server,pixelipo/server,bluelml/core,owncloud/core,nextcloud/server,pollopolea/core,Ardinis/server,owncloud/core,whitekiba/server,cernbox/core,cernbox/core,Ardinis/server,pmattern/server,andreas-p/nextcloud-server,xx621998xx/server,endsguy/server,xx621998xx/server,jbicha/server,andreas-p/nextcloud-server,pmattern/server,sharidas/core,michaelletzgus/nextcloud-server,pollopolea/core,phil-davis/core,endsguy/server,IljaN/core,xx621998xx/server,cernbox/core,nextcloud/server,whitekiba/server,jbicha/server,IljaN/core,IljaN/core,sharidas/core,pmattern/server,IljaN/core,michaelletzgus/nextcloud-server,sharidas/core,endsguy/server,michaelletzgus/nextcloud-server,owncloud/core