Non-fatal error while restoring postgres database in Satellite 5.6

Issue

• During the Satellite Database restore procedure:

  rhn-satellite stop --exclude=postgresql ; db-control restore /var/satellite/BACKUP-POSTGRES/postgres-online-today.dump ;
  rhn-satellite start --exclude=postgresql
  

  The following ERROR was shown:

  [...]
  ** Restoring from file /var/satellite/BACKUP-POSTGRES/postgres-online-today.dump.
  pg_restore: [archiver (db)] Error while PROCESSING TOC:
  pg_restore: [archiver (db)] Error from TOC entry 3395; 2612 16389 PROCEDURAL LANGUAGE pltclu postgres
  pg_restore: [archiver (db)] could not execute query: ERROR:  language "pltclu" already exists
      Command was: CREATE PROCEDURAL LANGUAGE pltclu;
  WARNING: errors ignored on restore: 1
  Restoration complete.