diazo: use branch 1.x.

I am trying a refactory to Python 3 only on master.

sources.cfg

@@ -28,7 +28,7 @@ borg.localrole                      = git ${remotes:plone}/borg.localrole.git pu
 collective.monkeypatcher            = git ${remotes:plone}/collective.monkeypatcher.git pushurl=${remotes:plone_push}/collective.monkeypatcher.git branch=master
 collective.xmltestreport            = git ${remotes:collective}/collective.xmltestreport.git pushurl=${remotes:collective_push}/collective.xmltestreport.git branch=master
 collective.recipe.omelette          = git ${remotes:collective}/collective.recipe.omelette.git pushurl=${remotes:collective_push}/collective.recipe.omelette.git branch=master
-diazo                               = git ${remotes:plone}/diazo.git pushurl=${remotes:plone_push}/diazo.git branch=master
+diazo                               = git ${remotes:plone}/diazo.git pushurl=${remotes:plone_push}/diazo.git branch=1.x
 five.customerize                    = git ${remotes:zope}/five.customerize.git pushurl=${remotes:zope_push}/five.customerize.git branch=2.x
 five.intid                          = git ${remotes:plone}/five.intid.git pushurl=${remotes:plone_push}/five.intid.git branch=1.x
 i18ndude                            = git ${remotes:collective}/i18ndude.git pushurl=${remotes:collective_push}/i18ndude.git branch=5.x