files_imageviewer: Double encode paths. Fixes oc-1016.
files_imageviewer: Double encode paths. Fixes oc-1016.

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