textproc/docbook-xsl: update 1.76.1 -> 1.79.1

PR: 221094
Submitted by: Alberto Mijares <amijaresp@gmail.com>
Approved by: gabor (maintainer timeout)
Relnotes: https://sourceforge.net/projects/docbook/files/docbook-xsl/1.79.1/

	  https://sourceforge.net/projects/docbook/files/docbook-xsl/1.78.1/
	  https://sourceforge.net/projects/docbook/files/docbook-xsl/1.77.1/