ProjectExplorer: Fix shutting down unreachable remote processes

We forgot to reset the state, which gave us a permanently broken run
control, preventing re-starting the application, among other things.

Change-Id: I7c168e31e015fdf7002c57aba0ed2178437a15ae
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/projectexplorer/runcontrol.cpp

@@ -1308,8 +1308,10 @@ void SimpleTargetRunnerPrivate::stop()
         case Run:
             m_process.stop();
             if (!m_process.waitForFinished(2000)) { // TODO: it may freeze on some devices
-                    QTC_CHECK(false); // Shouldn't happen, just emergency handling
+                q->appendMessage(Tr::tr("Remote process did not finish in time. "
+                                        "Connectivity lost?"), ErrorMessageFormat);
                 m_process.close();
+                m_state = Inactive;
                 forwardDone();
             }
             break;