No need to use rebootstrap nor zcbworkarounds

Those extensions are good in case really complex buildouts.

stack/flask.cfg

 # Stack for Flask microframework: http://flask.pocoo.org/
 [buildout]
-
-extensions =
-  slapos.rebootstrap
-  slapos.zcbworkarounds
-  
 extends =
   ../component/python-2.7/buildout.cfg
   ../component/lxml-python/buildout.cfg
-  
+
 # Use only quite well working sites.
 allow-hosts =
   *.nexedi.org
@@ -40,4 +35,4 @@ python = python2.7
 
 [rebootstrap]
 version = 1
-section = python2.7
\ No newline at end of file
+section = python2.7