If one of the OpenSSL GPG keys does not load, do not fail

Most keys load fine, but if one doesn't, everything fails. The package
will still verify OK even if we have just a subset of keys installed, be
more permissive...

deps/rabbitmq_prometheus/Dockerfile

@@ -61,7 +61,7 @@ RUN set -eux; \
 	wget --progress dot:giga --output-document "$OPENSSL_PATH.tar.gz" "$OPENSSL_SOURCE_URL"; \
 	export GNUPGHOME="$(mktemp -d)"; \
 	for key in $OPENSSL_PGP_KEY_IDS; do \
-		gpg --batch --keyserver "$PGP_KEYSERVER" --recv-keys "$key"; \
+		gpg --batch --keyserver "$PGP_KEYSERVER" --recv-keys "$key" || true; \
 	done; \
 	gpg --batch --verify "$OPENSSL_PATH.tar.gz.asc" "$OPENSSL_PATH.tar.gz"; \
 	gpgconf --kill all; \