Drop root for Zaqar service

Change-Id: I59797a8539406e478f6953a9aa0c933e73eb5892
Partially-Implements: blueprint drop-root

docker/zaqar/Dockerfile.j2

@@ -24,3 +24,5 @@ COPY extend_start.sh /usr/local/bin/kolla_extend_start
 RUN chmod 755 /usr/local/bin/kolla_extend_start
 
 {{ include_footer }}
+
+USER zaqar

docker/zaqar/extend_start.sh

@@ -3,6 +3,6 @@
 # Bootstrap and exit if KOLLA_BOOTSTRAP variable is set. This catches all cases
 # of the KOLLA_BOOTSTRAP variable being set, including empty.
 if [[ "${!KOLLA_BOOTSTRAP[@]}" ]]; then
-    sudo -H -u zaqar zaqar-manage db_sync
+    zaqar zaqar-manage db_sync
     exit 0
 fi