Port number when setting up Grafana with http not shown correctly

[kdhamric]

AC1: As a user setting up Grafana Tempo via HTTP,
the warning message about the default port does not seem correct
as it appears to expect the grpc port

AC2: As a user setting up Grafana Tempo via HTTP,
I would want the test connection to verify that I am talking to Graafana Tempo
and not a random http server (google.com in this example)
by querying a known resource on the server (list of traces, etc)

When setting up Grafana Tempo with a http address, if no port is entered our error messages are misleading as it does not show a port number (perhaps is should default to 443 for https, 80 for http):