patches/PythonScript.py: add getter for proxy roles.

product/ERP5Type/patches/PythonScript.py

@@ -56,6 +56,8 @@ def pyscript_getBody(self):
   return self._body
 def pyscript_getParams(self):
   return self._params
-
+def pyscript_getProxyRole(self):
+  return self._proxy_roles
 PythonScript.getBody = pyscript_getBody
 PythonScript.getParams = pyscript_getParams
+PythonScript.getProxyRole = pyscript_getProxyRole