refine network bytes of summaries, remove the lo data.

@@ -406,12 +406,17 @@ int SrsApiSummaries::do_process_request(SrsSocket* skt, SrsHttpMessage* req)
     int nb_n = srs_get_network_devices_count();
     for (int i = 0; i < nb_n; i++) {
         SrsNetworkDevices& o = n[i];
-        if (o.ok) {
-            n_ok = true;
-            nr_bytes += o.rbytes;
-            ns_bytes += o.sbytes;
-            n_sample_time = o.sample_time;
+        
+        // ignore the lo interface.
+        std::string inter = o.name;
+        if (!o.ok || inter == "lo") {
+            continue;
         }
+        
+        n_ok = true;
+        nr_bytes += o.rbytes;
+        ns_bytes += o.sbytes;
+        n_sample_time = o.sample_time;
     }
     
     ss << JOBJECT_START

@@ -509,6 +509,7 @@ void srs_update_network_devices()
                 
             if (ret == 17) {
                 r.ok = true;
+                r.name[sizeof(r.name) - 1] = 0;
                 _nb_srs_system_network_devices = i + 1;
                 r.sample_time = srs_get_system_time_ms();
             }