web: avoid proxy to connect to the local gRPC server (#4572)
web: avoid proxy to connect to the local gRPC server (#4572)

By default the gRPC client of the REST API gateway relies on the
HTTP_PROXY variable to connect to the local gRPC server which isn't
desired as the server runs in the same process. This change uses a
custom dialer that connects directly to the server's address.

Signed-off-by: Simon Pasquier <38e2d22e48be18381a59028f88390cad04670376@redhat.com>
keegancsmith/prometheus,prometheus/prometheus,Gouthamve/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,kangwoo/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,Gouthamve/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,alileza/prometheus,prometheus/prometheus,Gouthamve/prometheus,prometheus/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,alileza/prometheus,keegancsmith/prometheus,kangwoo/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,Gouthamve/prometheus