[Sat6] "WARNING: Unresolved specs during Gem::Specification.reset: multi_json (>= 1.3.6) " when upgrading Satellite

Issue

• There are two different scenarios where this error can be observed.
• When Changing the Proxy details in the Satellite server from old to new;

satellite-installer --katello-proxy-url=https://proxy1.exmaple.com --katello-proxy-port=10194

      WARN: Unresolved specs during Gem::Specification.reset:
      multi_json (>= 1.3.6)
      WARN: Clearing out unresolved specs.

• When upgrading Satellite 6, it gives a warning;

# satellite-installer --scenario satellite --upgrade

WARN: Unresolved specs during Gem::Specification.reset:

      multi_json (>= 1.3.6)

WARN: Clearing out unresolved specs.

Please report a bug if this causes problems.