Fixed building of the frcsim-libwpilibsim-cpp deb.

There is still a bug where the examples have been updated to use 0 based
joysticks, but the simulation libraries have not been updated. I'll fix
that as a separate commit focused on fixing the joystick APIs.

Change-Id: I3b358e67b7fa18b30d1fd2b53098659cfefdfd76

wpilibc/wpilibC++Sim/src/Timer.cpp

@@ -182,6 +182,14 @@ double Timer::GetFPGATimestamp()
 	return wpilib::internal::simTime;
 }
 
+/*
+ * Not in a match.
+ */
+double Timer::GetMatchTime()
+{
+	return Timer::GetFPGATimestamp();
+}
+
 // Internal function that reads the PPC timestamp counter.
 extern "C"
 {