fix otlp grpc exporter bug when no scheme is passed in

[codeboten]

Description

When an endpoint without a protocol is passed in, urlparse sets the host as the scheme and leaves the net location empty. This changes catches that and skips setting the endpoint in that case.

Fixes #1801

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

Does This PR Require a Contrib Repo Change?

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[ocelotl]

Approving, but I think the interface is not intuitive. We have insecure which does not have a default value, if it is not set, then it is defined depending on the protocol or lack of it in the endpoint. So, we have 2 ways of setting insecure, one overrides the other. This is not documented (which is easy to fix), but I wonder if we would be better without this insecure argument at all.

[codeboten]

@ocelotl yes I think the insecure parameter should be removed but I didn't want to break backwards compatibility there.

[ocelotl]

@ocelotl yes I think the insecure parameter should be removed but I didn't want to break backwards compatibility there.

Maybe we should ignore the protocol at all, then?

[codeboten]

Maybe we should ignore the protocol at all, then?

@ocelotl Using the protocol to determine secure/insecure is part of the specification.