VOL-3978 - update to go 1.16.3

Change-Id: I4a1c78722b3e4019dfd288fa9c89b7d90924050a
diff --git a/docker/Dockerfile.ofagent-go b/docker/Dockerfile.ofagent-go
index 663a0ae..09bbf4c 100644
--- a/docker/Dockerfile.ofagent-go
+++ b/docker/Dockerfile.ofagent-go
@@ -15,7 +15,7 @@
 # -------------
 # Build stage
 
-FROM --platform=linux/amd64  golang:1.13.8-alpine3.11 AS dev
+FROM --platform=linux/amd64 golang:1.16.3-alpine3.13 AS dev
 
 WORKDIR /go/src
 COPY . .