Fixes the following Sphinx warning (treated as error) starting
with 5.0 release:
Warning, treated as error: Invalid configuration value found:
'language = None'. Update your configuration to a valid langauge
code. Falling back to 'en' (English).
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>
Change-Id: I5d303131925c79757370864cc179cbe8154a2f4d
#
# This is also used if you do content translation via gettext catalogs.
# Usually you set "language" from the command line for these cases.
-language = None
+language = 'en'
# There are two options for replacing |today|: either, you set today to some
# non-false value, then it is used: