Normalize main(..) routines for WinUWP

In order to support WinUWP platform, all main(..) routines must be normalized to the formal int main(int argc, char* argv[]) form. A platform wrapper main is auto-created linking against the default main(...). This can only work if the linkage is exactly matching the proper formal definition and not a loosely defined main(...) alternative.

Bug: webrtc:8608
Change-Id: I606663aaea7df1792c7c5636279617b8926fa5cc
Reviewed-on: https://webrtc-review.googlesource.com/28721
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21229}

rtc_tools/network_tester/server.cc

@@ -10,10 +10,11 @@
 
 #include "rtc_tools/network_tester/test_controller.h"
 
-int main() {
+int main(int /*argn*/, char* /*argv*/ []) {
   webrtc::TestController server(9090, 9090, "server_config.dat",
                                 "server_packet_log.dat");
   while (!server.IsTestDone()) {
     server.Run();
   }
+  return 0;
 }