[RTM] Correct addFromCurrentRequest

[stefanheimes]

Description

This fix a problem where the request is null and the whole function addFromCurrentRequest will end in an "Call to a member function all() on null"-error.

@zonky2 and @discordier: I think we have to check all request calls for this error. This error happens, because I call the list module over the console, 'cause I create a PDF out of it.

Checklist

• [x] Read and understood the CONTRIBUTING guidelines
• [ ] Created tests, if possible
• [ ] All tests passing
• [x] Extended the README / documentation, if necessary
• [ ] Added myself to the @authors in touched PHP files
• [ ] Checked the changes with phpcq and introduced no new issues

[zonky2]

@stefanheimes Check author validation