doc/man: Do not install man *.rst files

doc/man: Do not install man *.rst files

When the man page got split up into several .rst files, these files got
listed into dist_doc_DATA=.  This variable will both distribute (package
in the source tarball) and install these files into /usr/share/doc.
This was not intended, and it duplicates the content and makes the doc
dir quite messy.

By moving these files to dist_noinst_DATA= instead, these files are
still distributed but not installed via 'make install'.

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200719114853.24168-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20476.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>