debugger: Reset breakpoint skip on boot

Fixes an issue where the first breakpoint after rebooting a game may
be skipped if the following sequence takes place:
 - The first breakpoint after booting the game is triggered once.
 - The user hits run to resume the game
 - The user reboots the game without any other breakpoint being
 triggered.

pcsx2/gui/AppMain.cpp

@@ -1089,6 +1089,7 @@ protected:
 
 		CoreThread.ResetQuick();
 		symbolMap.Clear();
+		CBreakPoints::SetSkipFirst(0);
 
 		CDVDsys_SetFile(CDVD_SourceType::Iso, g_Conf->CurrentIso );
 		if( m_UseCDVDsrc )