[BUG] contrib/gomodule/redigo: Passed context is ignored if not given in the args

[ghost]

The redis.Conn returned by DialContext() ignore the explicit context given as first argument of DoContext().

Version of dd-trace-go

All

Describe what happened:

Span are correctly created but are not attached to the parent span given in the context.

Describe what you expected:

Created span should be attached to the parent span given in the context.

Steps to reproduce the issue:

client, _ := redigotrace.Dial("tcp", "127.0.0.1:6379", WithServiceName("my-service"))

span, ctx := tracer.StartSpanFromContext(context.Background(), "test")
defer span.Finish()

_, _ = redis.DoContext(client, ctx, "SET", "ONE", "TWO")

[zarirhamza]

Closing due to PR being merged successfully, thank you for all your hard work!