Exit from upgrade without reporting error
Exit from upgrade without reporting error

As reported at https://help.nextcloud.com/t/silent-mode-for-occ-upgrade/2120 we should exit with a return value of 0 (zero) if the current instance is already up to date so that automatic deployment tools don't recognize that as an error.
endsguy/server,pixelipo/server,whitekiba/server,jbicha/server,pmattern/server,pixelipo/server,michaelletzgus/nextcloud-server,xx621998xx/server,pixelipo/server,pmattern/server,jbicha/server,michaelletzgus/nextcloud-server,Ardinis/server,endsguy/server,pixelipo/server,endsguy/server,xx621998xx/server,nextcloud/server,nextcloud/server,whitekiba/server,pmattern/server,andreas-p/nextcloud-server,michaelletzgus/nextcloud-server,whitekiba/server,nextcloud/server,endsguy/server,Ardinis/server,endsguy/server,pmattern/server,nextcloud/server,jbicha/server,Ardinis/server,Ardinis/server,michaelletzgus/nextcloud-server,xx621998xx/server,andreas-p/nextcloud-server,whitekiba/server,pmattern/server,Ardinis/server,xx621998xx/server,andreas-p/nextcloud-server,xx621998xx/server,andreas-p/nextcloud-server,jbicha/server,pixelipo/server,whitekiba/server,jbicha/server,andreas-p/nextcloud-server