chore: set GOPROXY with default value (#463)

Signed-off-by: Jim Ma <majinjing3@gmail.com>

hack/build.sh

@@ -11,6 +11,7 @@ MANAGER_BINARY_NAME=manager
 
 PKG=d7y.io/dragonfly/v2
 BUILD_IMAGE=golang:1.15.8
+GOPROXY=${GOPROXY:-}
 DATE=$(date "+%Y%m%d-%H:%M:%S")
 
 curDir=$(cd "$(dirname "$0")" && pwd)

hack/docker-build.sh

@@ -6,6 +6,7 @@ set -o pipefail
 
 D7Y_VERSION=${D7Y_VERSION:-"latest"}
 D7Y_REGISTRY=${D7Y_REGISTRY:-d7yio}
+GOPROXY=${GOPROXY:-}
 curDir=$(cd "$(dirname "$0")" && pwd)
 IMAGES_DIR="build/images"
 cd "${curDir}/../" || return