Add vim nginx ft to nginx config files

conf/http-base.conf

@@ -1,3 +1,5 @@
+# vim: ft=nginx
+
 types_hash_max_size 2048;
 include /usr/local/nginx/conf/mime.types.default;
 
@@ -30,4 +32,4 @@ upstream build_manager_controller_server {
 
 upstream build_manager_websocket_server {
     server localhost:8787;
-}
+}