Added timer fix suggested by Terapevt to avoid incorrect signed/unsigned comparison later.

git-svn-id: https://ja2svn.mooo.com/source/ja2/trunk/GameSource/ja2_v1.13/Build@9157 3b4a5df2-a311-0410-b5c6-a8a6f20db521

Utils/Timer Control.cpp

@@ -209,6 +209,10 @@ void CALLBACK TimeProc( UINT uID,	UINT uMsg, DWORD dwUser, DWORD dw1,	DWORD dw2
 
 				guiBaseJA2Clock += BASETIMESLICE;
 
+				// Terapevt suggested fix
+				if ((INT32)guiBaseJA2Clock < 0)
+					guiBaseJA2Clock = 0;
+
 				// detect overflow
 				if (uiOldClock > guiBaseJA2Clock)
 				{