Use config newline setting in system attribute evaluation

- Bump PORTREVISION for package change

It fixes comms/fldigi build without extra \r removal.

Problems seen with inconsistent newlines in the Table Of Contents HTML pulled in
from the configuration file. While the rest of the contents in the resulting
HTML file honored the newline style configured by the user, this specific
snippet of HTML always used "\r\n".

This root of this problem existed for some time, but in earlier versions, the
newline style was always "\n". The symptoms changed as a side effect of the
issue "Extra line padding in source and literal blocks". In this issue, the
newline style changed to "\r\n", and was noticed by users.

Change the System Attribute Evaluation function to use the newline setting from
the global "config" instead of using the default newline.

PR:		251329
Reported by:	db
Obtained from:	8313e45cc7

textproc/asciidoc/Makefile

@@ -3,6 +3,7 @@
 
 PORTNAME=	asciidoc
 PORTVERSION=	9.0.4
+PORTREVISION=	1
 CATEGORIES=	textproc
 MASTER_SITES=	https://github.com/asciidoc/asciidoc-py3/releases/download/${PORTVERSION}/
 

textproc/asciidoc/files/patch-asciidoc.py

@@ -0,0 +1,13 @@
+Obtained from:	https://github.com/asciidoc/asciidoc-py3/commit/8313e45cc78af30bb8df5d33311a7f2fdc50595c
+
+--- asciidoc.py.orig	2020-10-30 15:14:01 UTC
++++ asciidoc.py
+@@ -969,7 +969,7 @@ def system(name, args, is_macro=False, attrs=None):
+                 line = subs_attrs(line)
+                 if line is not None:
+                     result.append(line)
+-            result = DEFAULT_NEWLINE.join(result)
++            result = config.newline.join(result)
+     else:
+         assert False
+     if result and name in ('eval3', 'sys3'):