fix(config-ui): extra colon (#6238) (#6260)

Co-authored-by: 青湛 <0x1304570@gmail.com>
diff --git a/config-ui/nginx.conf b/config-ui/nginx.conf
index 85f89c6..412339c 100644
--- a/config-ui/nginx.conf
+++ b/config-ui/nginx.conf
@@ -2,7 +2,7 @@
   listen 4000;
   server_name localhost;
   absolute_redirect off;
-  client_max_body_size: 20m;
+  client_max_body_size 20m;
 
 ${SERVER_CONF}