The data output variable associated to a user task, if declared twice, is not being properly stored in the resulting BPMN (XML) file.
See more info at JBPM-8489

Acceptance Criteria

1. It shouldn't be possible to set more than one Input variable in Data I/O editor with the same name.
2. It should be possible to set any amount of Output variables with same name if it has different targets.

How to test at runtime

1. Create Start -> User Task -> End process
2. Create process variables `p_var1:String` and `p_var2:String`
3. For User Task set up Data Assignments in the following way:
4. Build and deploy the project, execute process, clam user task and provide any value for var1
5. When process is finished look at it's Process Info, both `p_var1:String` and `p_var2:String` should have the same value