Revert back to Alpine 3.12 for 32 bit systems

.github/workflows/build.yml

@@ -78,7 +78,7 @@ jobs:
             echo ::set-output name=platforms::linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7,linux/s390x,linux/ppc64le
           else
             echo ::set-output name=version::$BRANCH
-            echo ::set-output name=platforms::linux/amd64
+            echo ::set-output name=platforms::linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7
           fi
 
       - name: Build and push final image

Dockerfile

@@ -1,4 +1,4 @@
-ARG ALPINE_VERSION=3.13
+ARG ALPINE_VERSION=3.12
 ARG GO_VERSION=1.15
 ARG BUILDPLATFORM=linux/amd64