Merge "Fix doc build error" into stable/stein

doc/source/conf.py

@@ -16,6 +16,8 @@ import os
 import sys
 import pbr.version
 
+sys.setrecursionlimit(4000)
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.