Fixup invalid USES=python arguments.

Reported by:	tobik (in D19569)

games/ski/Makefile

@@ -11,7 +11,7 @@ COMMENT=	Skiing simulation with curses interface in python
 
 LICENSE=	BSD3CLAUSE
 
-USES=		python:3.2+:run
+USES=		python:3.2+,run
 NO_BUILD=	yes
 
 PLIST_FILES=	bin/${PORTNAME} \

net-mgmt/librenms-agent/Makefile

@@ -11,7 +11,7 @@ COMMENT=	Agents and plugins for librenms
 
 LICENSE=	GPLv2
 
-USES=		shebangfix python:2.7:run php:cli
+USES=		shebangfix python:2.7,run php:cli
 NO_ARCH=	yes
 
 USE_GITHUB=	yes

sysutils/py-python-consul/Makefile

@@ -20,7 +20,11 @@ RUN_DEPENDS=	${LOCALBASE}/bin/consul:sysutils/consul \
 				${PYTHON_PKGNAMEPREFIX}requests>=2.0.0:www/py-requests@${PY_FLAVOR} \
 				${PYTHON_PKGNAMEPREFIX}six>=1.4:devel/py-six@${PY_FLAVOR}
 
-USES=	python:2.7-3.6+
+IGNORE=	${IGNORE_${FLAVOR}}
+IGNORE_py35=	Does not work with Python 3.5
+
+# 2.7 or 3.6+, but it cannot be expressed right now.
+USES=	python
 
 USE_PYTHON=	distutils autoplist
 

sysutils/xen-guest-tools/Makefile

@@ -19,7 +19,7 @@ ONLY_FOR_ARCHS=		amd64 i386
 ONLY_FOR_ARCHS_REASON=	not yet ported to anything other than amd64 or i386
 CONFLICTS=	xen-tools-[0-9]*
 
-USES=		gmake python:2.7,configure perl5 gettext-runtime:build gettext-tools:build pkgconfig
+USES=		gmake python:2.7 perl5 gettext-runtime:build gettext-tools:build pkgconfig
 USE_PERL5=	build
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV+=	PYTHON=${PYTHON_CMD} PYTHON_PATH=${PYTHON_CMD}