devenv: Fix typo in nginix docker for mac (#18068)

devenv/docker/blocks/nginx_proxy_mac/docker-compose.yaml

@@ -5,7 +5,7 @@
 # root_url = %(protocol)s://%(domain)s:10080/grafana/
 
   nginxproxy:
-    build: docker/blocks/nginx_proxy
+    build: docker/blocks/nginx_proxy_mac
     ports:
       - "10080:10080"