Fixed issue with building Alpine armv7 image.

The runtime image was using a very old Alpine version.
This caused issues with the catatonit install

Now using the Balena armv7hf Alpine image for this.

docker/arm32v7/Dockerfile.alpine

@@ -65,7 +65,7 @@ RUN musl-strip target/armv7-unknown-linux-musleabihf/release/bitwarden_rs
 ######################## RUNTIME IMAGE  ########################
 # Create a new stage with a minimal image
 # because we already have a binary built
-FROM cmosh/alpine-arm:3.6
+FROM balenalib/armv7hf-alpine:3.12
 
 ENV ROCKET_ENV "staging"
 ENV ROCKET_PORT=80