remove unused reference

Author: mattsb42-aws

jose/backends/pycrypto_backend.py

@@ -149,7 +149,7 @@ def sign(self, msg):
     def verify(self, msg, sig):
         try:
             return PKCS1_v1_5.new(self.prepared_key).verify(self.hash_alg.new(msg), sig)
-        except Exception as e:
+        except Exception:
             return False
 
     def is_public(self):