fix(接口测试): 修复请求为connect类型时，保存报错的缺陷

--bug=1037069 --user=王孝刚 【接口测试】接口调试-保存请求-请求为connect类型-保存失败提示参数校验失败
https://www.tapd.cn/55049933/s/1475088

backend/framework/sdk/src/main/java/io/metersphere/sdk/constants/HttpMethodConstants.java

@@ -8,5 +8,6 @@ public enum HttpMethodConstants {
     PATCH,
     DELETE,
     OPTIONS,
-    TRACE
+    TRACE,
+    CONNECT
 }