Got these errors while installing and didn't find a specific answer for it. So, I'm offering the solutions as I found them in case anyone else encounters this:
Error: httpd24 conflicts with httpd-2.2.31-1.8.amzn1.x86_64Error: httpd24-tools conflicts with httpd-tools-2.2.34-1.16.amzn1.x86_64
The problem was encountered while trying to install https (mod24_ssl) over apache version 2.2.
If you install Apache using "yum install httpd" then you're going to get version 2.2. If you are getting this error then that's what you have. You'll have to upgrade to Apache 2.4. Hopefully you aren't so far in that you'll lose any work if you just delete version 2.2:
sudo yum remove httpdsudo yum remove httpd-toolssudo yum install httpd24