Add hack to allow server the setting of game cvar values that are important for playerstate prediction for legacy gamecode.

code/client/cl_parse.c

@@ -417,8 +417,14 @@ void CL_SystemInfoChanged( void ) {
 			// If this cvar may not be modified by a server discard the value.
 			if(!(cvar_flags & (CVAR_SYSTEMINFO | CVAR_SERVER_CREATED | CVAR_USER_CREATED)))
 			{
-				Com_Printf(S_COLOR_YELLOW "WARNING: server is not allowed to set %s=%s\n", key, value);
-				continue;
+#ifndef STANDALONE
+				if(Q_stricmp(key, "g_synchronousClients") && Q_stricmp(key, "pmove_fixed") &&
+				   Q_stricmp(key, "pmove_msec"))
+#endif
+				{
+					Com_Printf(S_COLOR_YELLOW "WARNING: server is not allowed to set %s=%s\n", key, value);
+					continue;
+				}
 			}
 
 			Cvar_SetSafe(key, value);