Description of problem:
./configure script finds docbook-utils and tries to use it to build manpages. that fails on `jw` error. the package is successfully built if docbook-utils are not present (or disabled via configure?)

If missing, then log reads:
checking for docbook2x-man... no
checking for docbook2man... no
checking for db2x_docbook2man... no
configure: WARNING: docbookx2-man/db2x_docbook2man not found, no manpages will be built
....

As found later in the log, manpage is prepackaged.

Version-Release number of selected component (if applicable):
nftables-0.8-4.el7

How reproducible:
always, environment

Steps to Reproduce:
have docbook-utils installed

Actual results:Making all in doc
make[2]: Entering directory `/home/test/rpmbuild/BUILD/nftables-0.8/doc'
docbook2man --xinclude nft.xml
Usage: jw [<options>] <sgml_file>
where <options> are:
  -f|--frontend <frontend>: 	 Specify the frontend (source format)
  				 (default is docbook)
  -b|--backend <backend>: 	 Specify the backend (destination format)
  				 (default is html)
  -c|--cat <file>: 		 Specify an extra SGML open catalog
  -n|--nostd: 			 Do not use the standard SGML open catalogs
  -d|--dsl <file>|default|none:	 Specify an alternate style sheet
  				 (default is to use the default stylesheet)
  -l|--dcl <file>: 		 Specify an alternate SGML declaration
  				 (usual ones like xml.dcl get detected automatically)
  -s|--sgmlbase <path>: 	 Change base directory for SGML distribution
  				 (usually /usr/share/sgml)
  -p|--parser <program>: 	 Specify the parser if several are installed
  				  (jade or openjade)
  -o|--output <directory>: 	 Set output directory
  -u|--nochunks: 		 Output only one big file
  				 (overrides the stylesheet settings)
  -i|--include <section>: 	 Specify a SGML marked section to include
  				 (should be marked as "ignore" in the SGML text)
  -w|--warning <warning_type>|list: Control warnings or display the allowed warning types
  -e|--errors <error_type>|list: Control errors or display the allowed error types
  -h|--help: 			 Print this help message and exit
  -V <variable[=value]>: 	 Set a variable
  -v|--version: 		 Print the version and exit
make[2]: *** [nft.8] Error 1
make[2]: Leaving directory `/home/test/rpmbuild/BUILD/nftables-0.8/doc'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/test/rpmbuild/BUILD/nftables-0.8'
make: *** [all] Error 2
error: Bad exit status from /var/tmp/rpm-tmp.eXSg5t (%build)

Expected results:


Additional info: