fix: [apache] docker pull output would get added to apache config file content

apache/hooks/web_proxy-relation-joined

@@ -5,7 +5,7 @@ set -e
 
 . lib/common
 
-apache_proxy_dir
+apache_proxy_dir || exit 1
 
 APACHE_CORE_RULES=$(relation-get apache-core-rules 2>/dev/null) || true
 if [ "$APACHE_CORE_RULES" ]; then

apache/lib/common

@@ -561,7 +561,7 @@ __vhost_proxy_statement() {
         ## First exposed port:
         base_image=$(service_base_docker_image "$BASE_SERVICE_NAME") || return 1
         if ! docker_has_image "$base_image"; then
-            docker pull "$base_image"
+            docker pull "$base_image" >&2
         fi
         first_exposed_port=$(image_exposed_ports_0 "$base_image" | tr '\0' '\n' | head -n 1 | cut -f 1 -d /) || return 1
         if [ -z "$first_exposed_port" ]; then