Update clash-meta.json

small fix

Author: HynoR

config/clash-meta.json

@@ -4,7 +4,7 @@
   "allow-lan": false,
   "unified-delay": true,
   "keep-alive-interval": 300,
-  "mode": "Rule",
+  "mode": "rule",
   "log-level": "info",
   "external-controller": "127.0.0.1:9090",
   "dns": {
@@ -18639,4 +18639,4 @@
     "GEOIP,CN,👉 国内网站",
     "MATCH,👉 例外网站"
   ]
-}
+}