Re generate armhf Dockerfile

Signed-off-by: Kentaro Hayashi <[email protected]>

Author: kenhys

v1.16/armhf/debian/Dockerfile

@@ -2,7 +2,7 @@
 # DO NOT EDIT THIS FILE DIRECTLY, USE /Dockerfile.template.erb
 
 # To set multiarch build for Docker hub automated build.
-FROM golang:alpine AS builder
+FROM --platform=$BUILDPLATFORM golang:alpine AS builder
 WORKDIR /go
 ENV QEMU_DOWNLOAD_SHA256 47ae430b0e7c25e1bde290ac447a720e2ea6c6e78cd84e44847edda289e020a8
 RUN apk add curl --no-cache