fix ui: add proxy_url in general settings

ui/src/locales/en.json

@@ -31,7 +31,8 @@
     "host": "Host",
     "port": "Port",
     "apikey": "API Key",
-    "timeout": "API Timeout (ms)"
+    "timeout": "API Timeout (ms)",
+    "proxy_url": "Proxy URL"
   },
   "transformers": {
     "title": "Custom Transformers",

ui/src/locales/zh.json

@@ -31,7 +31,8 @@
     "host": "主机",
     "port": "端口",
     "apikey": "API 密钥",
-    "timeout": "API 超时时间 (毫秒)"
+    "timeout": "API 超时时间 (毫秒)",
+    "proxy_url": "代理地址"
   },
   "transformers": {
     "title": "自定义转换器",