optimize collect remote address

Author: YangSen-qn

QiniuSDK/Http/Request/HttpClient/QNUploadSystemClient.m

@@ -102,8 +102,10 @@ - (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didFini
 
 #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
     if (@available(iOS 13.0, *)) {
-        self.requestMetrics.remoteAddress = transactionMetrics.remoteAddress;
-        self.requestMetrics.remotePort = transactionMetrics.remotePort;
+        if (transactionMetrics.remoteAddress) {
+            self.requestMetrics.remoteAddress = transactionMetrics.remoteAddress;
+            self.requestMetrics.remotePort = transactionMetrics.remotePort;
+        }
     }
 #endif