Fix segfault in fastcgi app

[daniel-falk]

If there are no query parameters specified, the application segfaulted since it did continue to try using the uri query list even if parsing them failed. This commit causes it to print the "Failed to parse .." text and then continue, waiting for the next request.

Describe your changes

Correct error handling.

Issue ticket number and link

Checklist before requesting a review

• [x] I have performed a self-review of my own code
• [x] I have verified that the code builds perfectly fine on my local system
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation

Maintainer notes

• [x] I have added tests that prove that the fix is effective
• [x] I have verified that the code change follows the style already available in the repository

[pataxis]

Thank you very much @daniel-falk for contributing with this bug fix!