Gdb: Notice when the gdb server process is exited

When terminating from within Qt Creator, we sometimes get a 'Quit'
message instead of 'Remote connection closed'.

Change-Id: I821d436813f1feacfe94ce85bc2175e3646dba27
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -1023,7 +1023,8 @@ void GdbEngine::handleResultRecord(GdbResponse *response)
                 QTC_CHECK(state() == InferiorRunOk);
                 notifyInferiorSpontaneousStop();
                 notifyEngineIll();
-            } else if (msg.startsWith("Remote connection closed")) {
+            } else if (msg.startsWith("Remote connection closed")
+                       || msg.startsWith("Quit")) {
                 // Can happen when the target exits (gdbserver)
                 notifyInferiorExited();
             } else {