Change "True Altitude" to "Alt (AGL)"

Why? The data will be the same, but it currently reads in a nice newbie friendly way. Otherwise we'll have people in here suggesting "Put layman terms on these things!"

Seems like a small, but useless change imho. The data won't change, just a label.

Closing this as an old MechJeb issue. Many MechJeb issues have had little interest in years, have been fixed for years, do not include adequate replication steps, refer to old problems which are no longer applicable, or are difficult to determine what the problem is. This issue is being closed for one of those reasons. We apologize for any inconvenience, but keeping the TODO list tidy helps the developers.

If this bug/issue is still a problem, please open a new issue. For bugs please try to include a Minimal, Complete, Verifiable Example that explains all the steps required to replicate the issue. A link to the KSP.log file should be ideally included, but is often not sufficient information. Screenshots or short videos are often the best way to show a bug.