Fix deprecation: Passing an argument to force an association to reload is now deprecated

What does this MR do?

Fixes deprecations: Passing an argument to force an association to reload is now deprecated and will be removed in Rails 5.1. Please call `reload_manual_association` instead. (called from block in manual_inverse_association at /builds/gitlab-org/gitlab-ce/app/models/concerns/manual_inverse_association.rb:9)

Passing an argument to force an association to reload is now deprecated and will be removed in Rails 5.1. Please call `reload` on the result collection proxy instead. (called from block (3 levels) in <top (required)> at /builds/gitlab-org/gitlab-ce/spec/models/gpg_key_spec.rb:202)

Passing an argument to force an association to reload is now deprecated and will be removed in Rails 5.1. Please call `reload` on the result collection proxy instead. (called from manual_actions at /builds/gitlab-org/gitlab-ce/spec/services/ci/process_pipeline_service_spec.rb:765)

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Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer