Require at least version 0.12 of werkzeug

Closes #12021
(grafted from 9f76ec6a7449de9286a96c48f7c12e8928e5e33e)

--HG--
branch : 6.0

trytond/setup.py

@@ -141,7 +141,7 @@ setup(name=name,
         'python-dateutil',
         'polib',
         'python-sql >= 0.5',
-        'werkzeug',
+        'werkzeug >= 0.12',
         'wrapt',
         'passlib >= 1.7.0',
         ],