Add stack trace to the logs when taskomatic fails to start

[wweellddeerr]

What does this PR change?

It improves taskomatic error logging by adding the stacktrace to the logs when taskomatic fails to start.

GUI diff

No difference.

• [x] DONE

Documentation

• No documentation needed: only internal and user invisible changes

• [x] DONE

Test coverage

• No tests: already covered

• [x] DONE

Links

• [x] DONE

Changelogs

Make sure the changelogs entries you are adding are compliant with https://github.com/uyuni-project/uyuni/wiki/Contributing#changelogs and https://github.com/uyuni-project/uyuni/wiki/Contributing#uyuni-projectuyuni-repository

If you don't need a changelog check, please mark this checkbox:

• [ ] No changelog needed

If you uncheck the checkbox after the PR is created, you will need to re-run changelog_test (see below)

Re-run a test

If you need to re-run a test, please mark the related checkbox, it will be unchecked automatically once it has re-run:

• [ ] Re-run test "changelog_test"
• [ ] Re-run test "backend_unittests_pgsql"
• [ ] Re-run test "java_pgsql_tests"
• [ ] Re-run test "schema_migration_test_pgsql"
• [ ] Re-run test "susemanager_unittests"
• [ ] Re-run test "javascript_lint"
• [ ] Re-run test "spacecmd_unittests"