SC2166: Link needs updating, wording needs hardening (upstream now states "have been removed" vs "marked obsolescent")

[udf2457]

SC2166 links to the old issue where it merely states:

The XSI extensions specifying the -a and -o binary primaries and the '(' and ')' operators have been marked obsolescent.

The present issue now states:

The -a and -o binary primaries and the '(' and ')' operators have been removed.