Sorry for the long wait.
I asked dev team to confirm, and it seems the procedure is straightforward (make sure you'll backup your container before proceeding and can revert the changes quickly):
1. Stop the service `# service httpd stop`
2. Back up your entire configuration directory, just in case some vital files get overwritten:
- `# cp -R /etc/httpd/ ~/httpd_config_backup`
- `# cp /etc/certs/httpd.* ~/httpd_config_backup/`
3. Run `# yum install httpd` - it should suggest you to upgrade the package and its dependencies
4. Verify the result; use `diff` to make sure the core files are still the same:
- `# diff -c ~/httpd_config_backup/conf/httpd.conf /etc/httpd/conf/httpd.conf`
- `# diff -c ~/httpd_config_backup/conf.d/https_gluu.conf /etc/httpd/conf.d/https_gluu.conf`
- `# diff ~/httpd_config_backup/httpd.key /etc/certs/httpd.key` (then the cert file as well)
5. Start it again `# service httpd start`
You can check version before and after with `# yum info httpd` or `# httpd -V` to make sure it worked.