[Bug libbacktrace/105721] libbacktrace: update README

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105721

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |ian at airs dot com

--- Comment #2 from Ian Lance Taylor <ian at airs dot com> ---
Thanks, fixed.