Description of problem:

OpenShift Toolkit extension failing to connect custom-devfile-registry

1. It does not allow from UI to add custom-devfile-registry url. Always fails with error `Invalid Registry URL`.

2. To workaround 1st issue, We can add custom-devfile-registry by manually updating `/home/user/.odo/preference.yaml` file, it already contains DefaultDevfileRegistry entry. It do get added successfully but further it always tries to connect DefaultDevfileRegistry. Cannot delete DefaultDevfileRegistry it recreates it.

3. To workaround 2nd Issue, We need to update `/home/user/.odo/preference.yaml` with custom-devfile-registry url in place of DefaultDevfileRegistry, means replace registry.devfile.io with custom-devfile-registry url.

Prerequisites (if any, like setup, operators/versions): Any

Steps to Reproduce

• Setup custom-devfile-registry using devfile.io custom-registry or via Registry Operator
• Create any workspace and install OpenShift toolkit
• By default OpenShift toolkit only add DefaultDevfileRegistry registry.devfile.io
• Add new custom-registry in OpenShift toolkit

Actual results:

Fails with error Invalid Registry URL

Expected results:

Adds cusom-registry successfully

Reproducibility (Always/Intermittent/Only Once): Always

Acceptance criteria: 

Definition of Done:

Build Details:

Additional info (Such as Logs, Screenshots, etc):

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