Fix uninitialized AppID.

This would cause clients to complain that their certs cannot be used
becuase they were for different "apps".

We probably need to add an interface to set this, so that this code
can properly interop with the Steam code running a real app.

src/steamnetworkingsockets/clientlib/csteamnetworkingsockets.cpp

@@ -288,6 +288,11 @@ bool CSteamNetworkingSockets::BInitGameNetworkingSockets( const SteamNetworkingI
 	else
 		CacheIdentity();
 
+	// Dummy AppID.  (Zero is a reserved value, don't use that.)
+	// If we want to be able to interop with the Steam code,
+	// we're going to need a way to set this, probably.
+	m_nAppID = 1;
+
 	return true;
 }
 #endif