No installer, but site is there? OK, setting up a production server (not live yet) and I am encountering a strange issue that I have not seen previously.

Issue:
Installed Craft on an Ubuntu 16.10 LAMP server. When all commands for installing were completed, I tested my site with its IP address to make sure everything worked and I got the following:


Then when I got to 192.168.5.254/public/index.php/admin/install -- which has worked on the two test servers I have built previously -- I get this:


An to make sure that I have tried another method of gaining access to the installer, I went here 192.168.5.254/admin which redirected to 192.168.5.254/admin/login, I get this:


Clearly Craft is working as these are not Apache 404's; however I never got the install screen at all. Just the homepage and login screen. Did I miss or mess something up during this specific install? 

As usual, if you need additional information, let me know I will post it in here for visual use. Thank you very much for your assistance!
As André pointed out, you only need to run the installer if you need Craft to create all of the necessary tables in a blank database.

If you've dumped your database from dev/staging and imported it into production, there is no need to run the installer, because the tables are already there.

If Craft sees someone try to load the installer on a site that already has a populated database like you have, it will return a 404.