Are you sure that you have the correct rights? Have a look at the demo that is running 3.17.3 as well and you can delete users there. So it is either a problem with your installation or with your user rights.
[edit] Just saw the bug report now and that this only happens when you are not the super admin. So I am not sure if this is a bug or a feature.
However, if you feel this is a bug, create a new bug report. Because the one you are referencing is for a completely different branch of Limesurvey.
I answer at the LimeSurvey forum in my spare time, I'm not a LimeSurvey GmbH employee.
No support via private message.
By the way, I don't think you want to post emails of members of the Central Bank of Costa Rica publicly, so I have deleted your screenshot. If you want to upload it again, please make sure that no one can see the email addresses.
I answer at the LimeSurvey forum in my spare time, I'm not a LimeSurvey GmbH employee.
No support via private message.