fix: typo in requires list of setup.py

close #410

Author: weakish

setup.py

@@ -11,7 +11,7 @@
     'six>=1.11.0',
     'qiniu>=7.1.4,<7.2.4',
     'requests>=2.20.0,<=2.22.0',
-    'urllib3>=1.24.3,<=1.25.3'
+    'urllib3>=1.24.3,<=1.25.3',
     'werkzeug',
     'gevent>=1.0.2,<2.0.0'
 ]