release-notes: fixup bad conflict resolution in bef6bef

/cc #19324.

nixos/doc/manual/release-notes/rl-1703.xml

···
       which prevents ptracing non-child processes.
       This means you will not be able to attach gdb to an existing process,
       but will need to start that process from gdb (so it is a child).
+    </para>
   </listitem>
 
   <listitem>