Comment # 3 on bug 1048692 from Stefan Knorr not reading bug mail

Added a new section:

> 2.1.5 GCC 6 Package Versions Match Packages Shipped with SLE 12 SP3
> 
> openSUSE Leap 42.2 accidentally shipped with a newer version of GCC 6 than was shipped with SUSE Linux Enterprise at the time. This has been corrected for openSUSE Leap 42.3 which ships with the same versions of GCC 6 packages as SUSE Linux Enterprise 12 SP3.
> However, if GCC 6 packages are installed, this leads to forced package downgrades during the operating system upgrade.

-> Fixed. Feel free to reopen if you need wording changes.