[macros] Fix PDF links to clauses and annexes

Such links were pointing to immediately after the clause
or annex title, not to immediately before them. The issue
was introduced with commit beb8815.

Fixes NB JP 014 and JP 015 (C++20 DIS)

Author: jensmaurer

source/macros.tex

@@ -70,8 +70,7 @@
 % Set the xref label for a clause to be "Clause n", not just "n".
 \makeatletter
 \newcommand{\customlabel}[2]{%
-\protected@write \@auxout {}{\string \newlabel {#1}{{#2}{\thepage}{#2}{#1}{}} }%
-\hypertarget{#1}{}%
+\@bsphack \begingroup \protected@edef \@currentlabel {\protect \M@TitleReference{#2}{\M@currentTitle}}\MNR@label{#1}\endgroup \@esphack%
 }
 \makeatother
 \newcommand{\clauselabel}[1]{\customlabel{#1}{Clause \thechapter}}