Image location is not always set correctly when creating a texture with drag and drop

Image location is not always set correctly when creating the texture with drag and drop. This happens if the dragged image file is located for example in a separate asset folder under the project folder.

Steps to test:

1. Create a project
2. Add view3D
3. Open the asset importer by clicking "Add New Assets" button in the Assets tab
4. Locate and open the image you wish to import, e.g. the attached Cork1.png
5. In the "Add Resources" dialog click "Browse" button
6. In the opening "Target Directory" window create a new folder "assets" under the project and select it as a target directory
7. Click OK to import the image
8. Drag and drop the image from the asset tab to cubeMaterial in the navigator
9. -> Texture is created but the image location is not set correctly for it
10. Click texture in the navigator
11. In the properties view, select "assets/Cork1.png" from the Image -> Source dropdown menu to set the source correctly