security/obfsproxy: Make argparse a conditional dependency

Backport a patch to setup.py making argparse a conditional dependency
to fix the following error at runtime:

pkg_resources.DistributionNotFound: The 'argparse' distribution was not found and is required by obfsproxy

While I'm here, pet portlint, USE_* comes before USES. Bump PORTREVISION.

PR:		223320
Submitted by:	cpm
Reported by:	Hadi <rezaee.hadi@gmail.com>
Approved by:	cs (maintainer timeout, 2 weeks)

security/obfsproxy/Makefile

@@ -3,7 +3,7 @@
 
 PORTNAME=	obfsproxy
 PORTVERSION=	0.2.13
-PORTREVISION=	1
+PORTREVISION=	2
 PORTEPOCH=	1
 CATEGORIES=	security net python
 MASTER_SITES=	http://www.c-s.li/ports/
@@ -18,8 +18,8 @@ RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pyptlib>=0.0.5:security/py-pyptlib \
 		${PYTHON_PKGNAMEPREFIX}twisted>=0:devel/py-twisted \
 		${PYTHON_PKGNAMEPREFIX}yaml>=0:devel/py-yaml
 
-USE_PYTHON=	distutils
 USES=		python
+USE_PYTHON=	distutils
 SUB_FILES=	pkg-message
 PYDISTUTILS_PKGNAME=obfsproxy
 

security/obfsproxy/files/patch-setup.py

@@ -1,11 +1,19 @@
---- setup.py.orig	2013-07-14 19:01:36.000000000 +0000
-+++ setup.py	2013-07-14 19:02:02.000000000 +0000
-@@ -31,7 +31,7 @@
+--- setup.py.orig	2017-11-03 11:21:18 UTC
++++ setup.py
+@@ -31,12 +31,14 @@ setup(
      install_requires = [
          'setuptools',
          'PyCrypto',
 -        'Twisted',
+-        'argparse',
 +        'Twisted_Core',
-         'argparse',
-         'pyptlib'
+         'pyptlib >= 0.0.6',
+         'pyyaml'
          ],
+ 
++    if sys.version_info < (2, 7):
++        install_requires.append('argparse')
++
+     extras_require = {
+         'SOCKS': ["txsocksx"]
+         }