license classifiers are deprecated and may become an error

diff --git a/setup.cfg b/setup.cfg
index 5c14b817..8376132e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -15,7 +15,6 @@ classifiers =
     Intended Audience :: Developers
     Intended Audience :: Information Technology
     Intended Audience :: System Administrators
-    License :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)
     Operating System :: MacOS :: MacOS X
     Operating System :: POSIX :: BSD :: FreeBSD
     Operating System :: POSIX :: Linux