Use abspath for celeryd to allow stat (refs #162)

contrib/debian/init.d/celeryd

@@ -80,7 +80,7 @@ set -e
 CELERYD_PID_FILE="/var/run/celeryd.pid"
 CELERYD_LOG_FILE="/var/log/celeryd.log"
 CELERYD_LOG_LEVEL="INFO"
-DEFAULT_CELERYD="celeryd"
+DEFAULT_CELERYD="/usr/bin/celeryd"
 
 # /etc/init.d/ssh: start and stop the celery task worker daemon.