Make HttpAppFrameworkImpl::quit() safe

[Demilivor]

Description:

It is possible to call HttpAppFrameworkImpl::quit() 2 times in a row directly or in the default signal handler.

Calling such code:

       app().quit();
       app().quit();

Execues double calling of such code in internal lambda:

    listenerManagerPtr_->stopListening();
    listenerManagerPtr_.reset();

And it leads to undefined behavior.

Fix:

Atomically check and set running_ flag earlier before queuing the lambda that resets pointers.