Fix tests which make remote HTTP calls

[jamezp]

The following tests make remote HTTP calls and should be changed:

• RestClientProxyTest.testHTTP2ByRegistration()
• RestClientProxyRedeployTest

These should not be making calls to remote HTTP endpoints. This results in issues with test stability at the least.

[hqqw2h-lgtm]

Hi, I'd like to work on this. I'll fix the tests that make remote HTTP calls to use local/mocked endpoints instead.