Control: tag -1 +pendingThe fix of this error is already available in git[1]. It will be in the next version.
But right now, you can add return statement in the begin of try_chconf_apache2 function in /usr/share/dhelp/maint-scripts/httpd.sh file on line 139. And you have to manually enable dhelp.conf Apache configuration file.
[1] https://anonscm.debian.org/cgit/collab-maint/dhelp.git/commit/?id=f33acd31ac972c43c17f298d7671ae80ec9157a2