python-pexpect: don't install async.py with python2

async.py is python3-only, so it fails to byte-compile with python2.

Fix #4480.

srcpkgs/python-pexpect/template

@@ -1,7 +1,7 @@
 # Template file for 'python-pexpect'
 pkgname=python-pexpect
 version=4.2.0
-revision=1
+revision=2
 noarch=yes
 wrksrc="${pkgname/python-}-${version}"
 build_style=python-module
@@ -17,6 +17,9 @@ distfiles="${PYPI_SITE}/p/pexpect/pexpect-${version}.tar.gz"
 checksum=bf6816b8cc8d301a499e7adf338828b39bc7548eb64dbed4dd410ed93d95f853
 
 post_install() {
+	# drop asyncio stuff from python2
+	# https://github.com/pexpect/pexpect/issues/290
+	rm -f ${DESTDIR}/usr/lib/python2*/site-packages/pexpect/async.py
 	vlicense LICENSE
 }