[bug]Incorrect overriding stateOptions when reusing a static value as getStateOptions()

[longquanzheng]

The value will be incorrect if there are two states in a workflow using the same static value for stateOptions(returned from getWorkflowStateOptions(), and one state has waitUntil but another doesnt -- the skipWaitUntil is internally stored in stateOptions and they will be overridden for each other.

This will totally mess up the workflow behavior -- the second state will get a wrong skipWaitUntil value.