ResourceWarning unclosed <socket.socket>

Hi,

When quitting a Bottle app using ^C and the built-in webserver, I get this message in the console:

/bottle.py:3119: ResourceWarning: unclosed <socket.socket fd=4, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 8080)>

Then, it hangs, and I have to ^C a second times to exit.

It should not be a big deal, but I never saw it before. Is it due to some recent changes? Thanks!