TT#50979 Stops using deprecated --init-replication in ngcp-update-db-schema

Kirill dropped support in commit to system-tools.git:

> commit 1602108442cbd3668ac6cf788ef487d732e7e594
> Author: Kirill Solomko <ksolomko@sipwise.com>
> Date:   Wed Mar 13 10:06:20 2019 +0100
>
>     TT#50979 ngcp-sync-db fix replication after reset slave

Change-Id: I3076c323fe32cef53a12d1e2e3c9dfc4874cfa02

ngcp-update-db-schema

@@ -253,7 +253,7 @@ if $RUN_SYNC_DB && ($NOT_REPLICATED_REV_APPLIED || [ -n "$AUTOMATED_INSTALL_MODE
           EXTRA_SYNC_DB_OPTS="--local-user=root --set-local-grants"
       fi
       # shellcheck disable=SC2086
-      if /usr/sbin/ngcp-sync-db --verbose --force --use-central-db --repl-mode "master-slave" --init-replication --databases "${PRX_SYNC_DBS}" --ssh-tunnel=33125 ${EXTRA_SYNC_DB_OPTS} --local-host=${LOCAL_DBHOST} --local-port=${LOCAL_DBPORT}; then
+      if /usr/sbin/ngcp-sync-db --verbose --force --use-central-db --repl-mode "master-slave" --databases "${PRX_SYNC_DBS}" --ssh-tunnel=33125 ${EXTRA_SYNC_DB_OPTS} --local-host=${LOCAL_DBHOST} --local-port=${LOCAL_DBPORT}; then
           echo "Syncing 'not_replicated' statements from the central node."
       else
           echo "Error: While syncing 'not_replicated' statements from the central node, please run ngcp-sync-db-wrapper manually to fix them." >&2