Create domain Model wizard does not take into account previous value from template

when creating a new sequential project, it creates a .dsl file with the following content:
```
name = org.eclipse.gemoc.example.k3fsm.K3fsm
ecore = platform:/resource/ecoreFilePath
k3 = qualified.class.name
```

then when trying to create a domain model project, it simply add a new value to the ecore entry

something like:
```
ecore = platform:/resource/ecoreFilePath,platform:/resource/org.eclipse.gemoc.example.k3fsm/model/k3fsm.ecore
```

It would be useful to detect that this value is actually a dummy value coming from the template and replace it with the new one.
Adding the value is still good but for next calls to the wizard of if it doesn't recognize the template.

Step to reproduce:
* File > New > Gemoc Sequential Xdsml project, Finish
* right click on the project, GEMOC Language > Create Domain Model Project for Language