Improve error handling when we have Rights issue

Let's take this example

We have this macro call

{{jira id="testlocaljiranoriquire" source="jql"}}
project = TEST
{{/jira}}

And the user used to send the request to JIRA don't have the rights to access to the TEST project.

In this case we will end with this error

which is not really explicit about what happen.

This issue is to improve this message when there are rights issue to provide a more explicit error why there are no result.