File python3.patch of Package libselinux

Index: libselinux-2.6/src/Makefile
===================================================================
--- libselinux-2.6.orig/src/Makefile	2016-10-14 17:31:26.000000000 +0200
+++ libselinux-2.6/src/Makefile	2018-03-22 11:33:36.527385495 +0100
@@ -1,7 +1,7 @@
 # Support building the Python bindings multiple times, against various Python
 # runtimes (e.g. Python 2 vs Python 3) by optionally prefixing the build
 # targets with "PYPREFIX":
-PYTHON ?= python
+PYTHON ?= python3
 PYPREFIX ?= $(notdir $(PYTHON))
 RUBY ?= ruby
 RUBYPREFIX ?= $(notdir $(RUBY))