Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1312004
Description of problem:
I am unable to update smart class parameter type from API from any to any.

Version-Release number of selected component (if applicable):
foreman-1.11.0-0.develop.201602171602gitd5b5059.el7.noarch

How reproducible:
Always

Steps to Reproduce:
1. Update smart class parameter type from API from any type to any other type.

#curl-X PUT -H "Content-Type: application/json" -d '{"parameter_type":"string"}' "https://<server_url>/api/smart_class_parameters/<param_id>" --insecure

Actual results:
Parameter Type is not updated.

Output:

"description":"","override":true,"parameter_type":"boolean","default_value":true,"hidden_value?":false,"hidden_value":"*****","use_puppet_default":false,"required":true,"validator_type":"","validator_rule":null,"merge_overrides":null,"merge_default":false,"avoid_duplicates":null,"override_value_order":"fqdn\nhostgroup\nos\ndomain","override_values_count":0,"created_at":"2016-02-25 12:07:30 UTC","updated_at":"2016-02-25 13:45:20 UTC","puppetclass_name":"nova::api","parameter":"admin_password","id":322,"puppetclass_id":37,"environments":[{"id":3,"name":"KT_Default_Organization_Dev_puppet_cv_3"},{"id":2,"name":"KT_Default_Organization_Library_puppet_cv_3"}],"puppetclass":{"id":37,"name":"nova::api","module_name":"nova"},"override_values":[]}

Expected results:
Parameter should be updated.

Additional info: