Show integration page if no integrations are configured

[silamon]

Proposed change

Fix #19436. When no integrations are configured, no messages are received and configEntries remain undefined. In this case, you end up with an instance where you can't configure any config flows since the loading spinner never finish. This change sets configEntries to an empty array so the page can load.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io