To fix version display in PDFs, move config changes to config-inited
event.
First config-inited is called, then
builder-inited is called after the builder is setup. The builder might
use values from the config to set internal values.
This happens with the latex builder that takes version and release and
puts them into internal values.
So far, openstackdocstheme used builder-inited and setting version and
release from the theme happened to late. Move all config settings to a
config-inited phase so that it is early - and thus the latex builder can
create PDFs with version numbers.
Change-Id: Icdd308ba13de56bab13e97e3afc6338a7181dcbf
957cee03f9