DB backups are created by incorrect postgres version

in https://github.com/syndesisio/syndesis/pull/7821, the image for backing up/restoring db is crunchydata/crunchy-pgdump:centos7-12.1-4.2.1 that is related to the 12.1 postgres version. However, we use 9.6 so this image should be changed to centos7-9.6.16-4.2.1 version to match with our version.

This blocks the manual restore procedure:

sh-4.2$ pg_restore -v -d syndesis_restore /tmp/syndesis-db2
pg_restore: [archiver] unsupported version (1.14) in file header