Use Sphinx 1.5 warning-is-error3.24.0

With pbr 2.0 and Sphinx 1.5, the setting for treat sphinx warnings as
errors is setting warning-is-error in build_sphinx section. Migrate the
setting from the old warnerrors one.

There are two issues:

- The `*` character is recognized as an emphasis character and must be
  escaped
- The index references modules that have since been removed

These are resolved.

Change-Id: Id078022c0f75bf8f162b693d260f67116eb6428b

1 files changed, 2 insertions, 4 deletions

diff --git a/setup.cfg b/setup.cfg
index 7ea22ca..a0302e0 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -22,13 +22,11 @@ classifier =
 packages =
     oslo_utils
 
-[pbr]
-warnerrors = true
-
 [build_sphinx]
+all-files = 1
+warning-is-error = 1
 source-dir = doc/source
 build-dir = doc/build
-all_files = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html