Description: Do not use the Internet to fetch DTD

Use '--nonet' flag in order to prevent xsltproc from using the Internet
to fetch DTDs, entities or documents.

Ported from offlineimap.

Author: Ilias Tsitsimpis <i.tsitsimpis@gmail.com>
Forwarded: not-needed

---

--- offlineimap3-0.0~git20201025.5e7b006.orig/docs/Makefile
+++ offlineimap3-0.0~git20201025.5e7b006/docs/Makefile
@@ -28,10 +28,10 @@ offlineimapui.html: offlineimapui.txt
 man: offlineimap.1 offlineimapui.7
 
 offlineimap.1: offlineimap.txt offlineimap.known_issues.txt
-	a2x -v -d manpage -f manpage $<
+	a2x --xsltproc-opts=-nonet -v -d manpage -f manpage $<
 
 offlineimapui.7: offlineimapui.txt
-	a2x -v -d manpage -f manpage $<
+	a2x --xsltproc-opts=-nonet -v -d manpage -f manpage $<
 
 api:
 	$(SPHINXBUILD) -b html -d html/doctrees doc-src html