Remove unused pngmath sphinx extension

The extension is not used, remove it.

Change-Id: I0720058e8d2235772b5bb82224b68b1b52e6060d

diff --git a/doc/source/conf.py b/doc/source/conf.py
index d8eb4a5bbb227f5b611af5e943cfae32ff14b073..d1e0e8e2e4d4750d15e64264eb5d4aa91f0d817c 100644 (file)
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -30,7 +30,6 @@ sys.path.insert(0, os.path.abspath('./'))
 extensions = ['sphinx.ext.autodoc',
               'ext.cinder_todo',
               'sphinx.ext.coverage',
-              'sphinx.ext.pngmath',
               'sphinx.ext.ifconfig',
               'sphinx.ext.graphviz',
               'oslosphinx',