stack/erp5: Drop stunnel.

Nothing uses it in this software release.

stack/erp5/buildout.cfg

@@ -41,7 +41,6 @@ extends =
   ../../component/scikit-learn/buildout.cfg
   ../../component/scikit-image/buildout.cfg
   ../../component/PyWavelets/buildout.cfg
-  ../../component/stunnel/buildout.cfg
   ../../component/subversion/buildout.cfg
   ../../component/tesseract/buildout.cfg
   ../../component/w3m/buildout.cfg
@@ -81,7 +80,6 @@ parts +=
   graphviz
   haproxy
   jsl
-  stunnel
   w3m
   poppler
   libpng
@@ -288,7 +286,6 @@ context =
     key sixtunnel_location 6tunnel:location
     key template_run_zelenium template-run-zelenium:target
     key egg_interpreter eggs:interpreter
-    key stunnel_location stunnel:location
     key template_apache_conf template-apache-backend-conf:target
     key template_balancer template-balancer:target
     key template_erp5 template-erp5:target