fixed missing ) after statement

[ertanyildiz]

There was no closing parenthesis on #579 in user_guide_src/source/incoming/incomingrequest.rst:243. I've added the missing ) to the line.

[michalsn]

Thanks, but there are two things.

• We can only merge commits that are signed. You can read more about it here: https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/signing.rst
• Also, for the future - if your changes don't involve any actual code from framework, you can use [ci skip] in your commit description to just skip Travis build.

[ertanyildiz]

@michalsn Thanks for your feedback. I have reopened the pull request as requested.