Reintroducing the logging::Manager's Terminate() method.

It doesn't do anything else than simply forwarding to FlushBuffers().

This is just for consistency in terminate_bro() where components get
their Terminate() called so that the main code doesn't need to know
anything more specific about what particular action to take at
shutdown.

src/logging/Manager.cc

@@ -1285,6 +1285,11 @@ void Manager::FlushBuffers()
 		}
 	}
 
+void Manager::Terminate()
+	{
+	FlushBuffers();
+	}
+
 // Timer which on dispatching rotates the filter.
 class RotationTimer : public Timer {
 public: