libidn-1.33 fails to build library when some doc tools are missing

[Jeffrey Walton]

I'm trying to build libidn to use with Wget. As far as I know Wget
does not require man pages. Wget will build just fine without them.

Building libidn-1.33 results in:

make[4]: Entering directory '/home/scripts/libidn-1.33/doc'
/bin/bash /home/scripts/libidn-1.33/build-aux/missing help2man \
        --name="Internationalized Domain Names command line tool" \
        --output=idn.1 ../src/idn
/home/scripts/libidn-1.33/build-aux/missing: line 81: help2man:
command not found
WARNING: 'help2man' is missing on your system.
         You should only need it if you modified a dependency of a man page.
         You may want to install the GNU Help2man package:
         <http://www.gnu.org/software/help2man/>
Makefile:2209: recipe for target 'idn.1' failed

Perhaps it would be a good idea to to avoid docs when tools are not present.