Fix build with Python 2.7

svn path=/head/; revision=543748

devel/py-curtsies/files/patch-setup.py

@@ -0,0 +1,11 @@
+--- setup.py.orig	2020-07-15 20:17:08 UTC
++++ setup.py
+@@ -16,7 +16,7 @@ setup(
+     name="curtsies",
+     version=version(),
+     description="Curses-like terminal wrapper, with colored strings!",
+-    long_description=open("readme.md", encoding="utf-8").read(),
++    long_description=io.open("readme.md", encoding="utf-8").read(),
+     long_description_content_type="text/markdown",
+     url="https://github.com/bpython/curtsies",
+     author="Thomas Ballinger",