完善Http客户端复用机制

src/Http/HttpRequester.h

@@ -39,6 +39,7 @@ public:
     HttpRequester();
     virtual ~HttpRequester();
     void startRequester(const string &url,const HttpRequesterResult &onResult,float timeOutSecond = 10);
+    void clear() override ;
 private:
     int64_t onResponseHeader(const string &status,const HttpHeader &headers) override;
     void onResponseBody(const char *buf,size_t size,size_t recvedSize,size_t totalSize)  override;