Description of problem:

Right now we have an inconsistency in the way we process the model folder path for a Data Connection.

If the model is in the root folder, we need to add a / slash to that field.

On the other hand, when the model is inside a folder in the bucket, we need to add that path without the first / slash.

Steps to Reproduce

1. Create a new model server
2. Add a data connection
3. Target a model in the root folder with /
4. The model should be deployed
5. Now deploy another model in some path, try to add it with /route/model
6. Check that this configuration will fail since we are adding the slash at the beginning of the path.