fixed error in setup.py

Author: ajoino

setup.py

@@ -27,7 +27,7 @@
             'Programming Language :: Python :: 3',
             'Programming Language :: Python :: 3.7',
             'Programming Language :: Python :: 3.8',
-            'Programming Language :: Python :: 3.9'
+            'Programming Language :: Python :: 3.9',
             'Operating System :: POSIX :: Linux',
             'License :: OSI Approved :: Eclipse Public License 2.0 (EPL-2.0)',
         ],