Use vanilla Alpine instead of Alpine+go for the registry image base.

Co-authored-by: Joe Lanford <[email protected]>

Author: benluddy

upstream-builder.Dockerfile

@@ -13,7 +13,7 @@ RUN GRPC_HEALTH_PROBE_VERSION=v0.3.2 && \
     wget -qO/bin/grpc_health_probe https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/${GRPC_HEALTH_PROBE_VERSION}/grpc_health_probe-linux-$(go env GOARCH) && \
     chmod +x /bin/grpc_health_probe
 
-FROM golang:1.13-alpine
+FROM alpine:3
 
 COPY --from=builder [ \
     "/bin/grpc_health_probe", \