ProjectExplorer: Remove wrong QTC_CHECK

Tools like ClangStaticAnalyzer do not operate on a running process,
so there is no valid process handle when they are 'stopping'.

Change-Id: I42754475f9c7c7367e0f4875c6f3348fd81fccf8
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/projectexplorer/runconfiguration.cpp

@@ -1132,7 +1132,6 @@ void RunControlPrivate::setState(State newState)
         emit q->started();
         break;
     case State::Stopped:
-        QTC_CHECK(applicationProcessHandle.isValid());
         q->setApplicationProcessHandle(Utils::ProcessHandle());
         toolRunner->onFinished();
         targetRunner->onFinished();