优化文件上传速度，增加请求头预校验功能

webcc/url.h

@@ -51,6 +51,12 @@ public:
     port_ = ToString(port);
   }
 
+  // Force Set
+  void ForceSet_Path(string_view path)
+  {
+    path_ = path;
+  }
+
   // Append a piece of path.
   void AppendPath(string_view piece, bool encode = false);