apt-get install ca-certificates for the release image stage

docker/Dockerfile.build

@@ -24,6 +24,10 @@ RUN cargo test --all --release; cd zebrad/; cargo build --release --features ena
 # Runner image
 FROM debian:buster-slim AS zebrad-release
 
+RUN apt-get update && \
+	apt-get install -y --no-install-recommends \
+	ca-certificates
+
 COPY --from=builder /zebra/target/release/zebrad /
 
 ARG CHECKPOINT_SYNC=true

docker/Dockerfile.test

@@ -2,7 +2,7 @@ FROM rust:buster
 
 RUN apt-get update && \
 	apt-get install -y --no-install-recommends \
-	make cmake g++ gcc llvm libclang-dev clang ca-certificates
+	make cmake g++ gcc llvm libclang-dev clang
 
 RUN mkdir /zebra
 WORKDIR /zebra