fix: [Widget Image] Remove oldurl string check since it's always a string and prevent the ObjectURL cleaning resulting in a memory leak.
fix: [Widget Image] Remove oldurl string check since it's always a string and prevent the ObjectURL cleaning resulting in a memory leak.

ipython/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets,jupyter-widgets/ipywidgets,ipython/ipywidgets,jupyter-widgets/ipywidgets