Test Failure: LogStash::Agent Agent execute options when `config.reload.automatic` is set to`FALSE` and successfully load the config converge only once

Jenkins test failure running compatibility tests on OpenSuse for version 6.x:

```
17:43:03 Failures:
17:43:03
17:43:03 1) LogStash::Agent Agent execute options when `config.reload.automatic` is set to`FALSE` and successfully load the config converge only once
17:43:03 Failure/Error: expect(source_loader.fetch_count).to eq(1)
17:43:03
17:43:03 expected: 1
17:43:03 got: 0
17:43:03
17:43:03 (compared using ==)
17:43:03 # /var/lib/jenkins/workspace/elastic+logstash+6.x+multijob-unix-compatibility/os/opensuse/logstash-core/spec/logstash/agent/converge_spec.rb:108:in `block in (root)'
17:43:03 # /var/lib/jenkins/workspace/elastic+logstash+6.x+multijob-unix-compatibility/os/opensuse/vendor/bundle/jruby/2.3.0/gems/rspec-wait-0.0.9/lib/rspec/wait.rb:46:in `block in /var/lib/jenkins/workspace/elastic+logstash+6.x+multijob-unix-compatibility/os/opensuse/vendor/bundle/jruby/2.3.0/gems/rspec-wait-0.0.9/lib/rspec/wait.rb'
17:43:03 # /var/lib/jenkins/workspace/elastic+logstash+6.x+multijob-unix-compatibility/os/opensuse/lib/bootstrap/rspec.rb:13:in `'
17:43:03
17:43:03 Finished in 7 minutes 23 seconds (files took 19.54 seconds to load)
17:43:03 3060 examples, 1 failure, 3 pending
17:43:03
17:43:03 Failed examples:
17:43:03
17:43:03 rspec /var/lib/jenkins/workspace/elastic+logstash+6.x+multijob-unix-compatibility/os/opensuse/logstash-core/spec/logstash/agent/converge_spec.rb:105 # LogStash::Agent Agent execute options when `config.reload.automatic` is set to`FALSE` and successfully load the config converge only once
17:43:03
17:43:03 Randomized with seed 56177
```

This test appears to have had some issues in the past:
#7737
#7392

Start with logstash-core/spec/logstash/agent/converge_spec.rb:105-108 and reproduce the reported compatibility failure on OpenSuse, focusing on why source_loader.fetch_count is 0 instead of 1. Review prior issues #7737 and #7392 for context; done means the affected test passes reliably in the 6.x compatibility suite.

Written by the indexing model from the issue text.