Description of problem:
The following error modal is displayed after I delete any (my custom created or predefined) of the datasources in DataSet perspective (see screenshot):

Error
User root has deleted the following resource default://master@datasets/definitions/c805471b-d9ff-4cc2-8025-57dba21b02b7.dset.

This is quite confusing, because above this modal there's notification "Item successfully deleted" and the data set seems to be deleted successfully (not shown in data set explorer anymore).

Version-Release number of selected component (if applicable):
kie-wb: 6.3.x snapshot

How reproducible:
Always

Steps to Reproduce:
1. Navigate to DataSets perspective
2. Expand any data set in DS Explorer
3. Click edit button
4. In data set editor panel that opens, click Delete button at the top right.

Actual results:
Modal with error (see above) displayed.

Expected results:
If deletion is successful, no modal should be dispalyed (the notification is enough).