fix game does not initialize when OS runs for longer than 30 days or so.

Special thanks to Yshxod for having the patience and debugging the game with me!

(cherry picked from commit a04a1b697b)

src/game/C4Application.cpp

@@ -836,7 +836,7 @@ bool C4Application::FullScreenMode()
 
 C4ApplicationGameTimer::C4ApplicationGameTimer()
 		: CStdMultimediaTimerProc(26),
-		tLastGameTick(0), iGameTickDelay(0)
+		tLastGameTick(C4TimeMilliseconds::NegativeInfinity), iGameTickDelay(0)
 {
 }