fixed token_service

src/data-hub/role-stage-discovery-microservice/app/services/token_service.py

 from security import security_util
 
 def verifyTokenRegular(token, required_scopes):
-    return decodeToken(token)
+    return security_util.decodeToken(token)
 
 def verifyTokenAdmin(token, required_scopes):
     # TODO call restGateway to verify the token