Update net/mitmproxy to 0.11.3 (pkg/49729 and pkg/497930)

[Leonardo Taccari <iamleot%gmail.com@localhost>]

Hello to all tech-pkg@ readers,
in the last days I have played with net/mitmproxy and while there I
updated it to the latest stable version (0.11.3).
I have attached all the patches needed in pkg/49729 and pkg/49730, they
are more or less trivial patches but to succesfully apply them it is
needed to:

 0. import wip/py-configargparse as devel/py-configargparse (packaged by
    me, it is my first Python package so please give a look to it and
    please complain enough with me if something is wrong :)).
    It should be noted that wip/py-configargparse is needed by the newer
    version of net/mitmproxy in order to avoid specifying
    mitm{dump,proxy} arguments every time (for more information please
    give a look to the mitmproxy changelog, also available in
    pkg/49730 and pkgsrc/wip/py-configargparse/DESCR).
 1. apply pkg/49729 to update net/py-netlib to the latest stable version
    (0.11.2). This version is needed by the latest stable version of
    mitmproxy.
 2. apply pkg/49730 to update net/mitmproxy and please remember to
    update the DEPENDS line regarding py-configargparse (just a
    s/wip/devel/ will be enough and also get rid of the XXX comment :)).

Sorry for the noise but I prefer the «repetita iuvant» approach because
after reading the two PRs these steps was not so obvious and so I
preferred to take some minutes to describe everything here to make
easier to update net/mitmproxy.


Thank you very much for your attention!
Ciao,
L.