aws-lambda-go/lambda appears to rewrite and break AWS_LAMBDA_RUNTIME_API URI scheme

[ryanblock]

Description of issue

When running a Go handler with the Lambda module (github.com/aws/aws-lambda-go/lambda), setting the env var of AWS_LAMBDA_RUNTIME_API to http://localhost:2222 results in the following error:

2023/03/27 20:44:58 failed to get the next invoke: Get "http://http//localhost:2222/2018-06-01/runtime/invocation/next": dial tcp: lookup http: no such host

It appears this module does not want a URI scheme (specifically: http://) specified, which appears to be at odds with how other official AWS libraries that make use of the Lambda Runtime API (and AWS_LAMBDA_RUNTIME_API env var) seem to work.

Expected result

Whatever is found in the AWS_LAMBDA_RUNTIME_API env var is exactly the URI that should be used preceding the /2018-06-01/runtime/invocation/next (and other) endpoint(s).

Steps to reproduce

Run a module that imports github.com/aws/aws-lambda-go/lambda and ensure that your AWS_LAMBDA_RUNTIME_API starts with http://.