Remove universal wheel building

- Remove obsolete sections from setup.cfg:
  * Wheel is not needed for python 3 only repo

Change-Id: I95a717b873c8c21eeec4617b66c42cd6dbf226b2
diff --git a/setup.cfg b/setup.cfg
index 61803a4..04511e1 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -49,5 +49,3 @@
 oslo.config.opts =
     tempest.config = tempest.config:list_opts
 
-[wheel]
-universal = 1