hgweb: don't pass empty response chunks on
hgweb internals will often produce empty writes - especially when returning
compressed data. hgweb is no middleware application and there is thus no
reason to pass them on to be processed in other layers.
.. Common link and substitution definitions.
.. |hg(1)| replace:: **hg**\ (1)
.. _hg(1): hg.1.html
.. |hgrc(5)| replace:: **hgrc**\ (5)
.. _hgrc(5): hgrc.5.html
.. |hgignore(5)| replace:: **hgignore**\ (5)
.. _hgignore(5): hgignore.5.html