Foreman Maintain

b'Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=2164080 \n\n*Description of problem:*\nUpgrade will fail during check-tftp-storage check with "no implicit conversion of nil into String"\n\nRunning preparation steps required to run the next scenarios\n================================================================================\nCheck whether system has any non Red Hat repositories (e.g.: EPEL) enabled: \n- Checking repositories enabled on the system [OK] \n--------------------------------------------------------------------------------\n\n\nRunning Checks before upgrading to Satellite 6.13\n================================================================================\nClean old Kernel and initramfs files from tftp-boot: [FAIL]\nno implicit conversion of nil into String\n...\n\n*Version-Release number of selected component (if applicable):*\n6.13.0 Snap 7\nrubygem-foreman_maintain-1.2.3-1.el8sat.noarch\n\n*How reproducible:*\ndeterministic\n\n*Steps to Reproduce:*\n1. Upgrade to 6.13 \n# satellite-maintain upgrade check --target-version 6.13\n\n*Actual results:*\nupgrade check fails\n\n*Expected results:*\nupgrade check succeeds\n\n*Additional info:*\nhttps://github.com/theforeman/foreman_maintain/blob/v1.2.3/definitions/checks/foreman_proxy/check_tftp_storage.rb#L45-L48\n\ndata⁰ is nil , db query needs to be adapted to 6.13\n\nforeman=> select s.value, s.default from settings s; \nERROR: column s.default does not exist\nLINE 1: select s.value, s.default from settings s;'