Fix IE8 issue when icon is not defined
Fix IE8 issue when icon is not defined

Sometimes no icon file is passed to replaceSVGIcon(), it showed an error
in IE8 and broke the code flow.

This fix adds a check whether the file name is set.

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