shift-enter should not error out when no cell is selected
shift-enter should not error out when no cell is selected

eskirk/jupyterlab,eskirk/jupyterlab,charnpreetsingh185/jupyterlab,charnpreetsingh185/jupyterlab,charnpreetsingh185/jupyterlab,TypeFox/jupyterlab,jupyter/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,eskirk/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,jupyter/jupyterlab,charnpreetsingh185/jupyterlab,eskirk/jupyterlab,jupyter/jupyterlab,TypeFox/jupyterlab,TypeFox/jupyterlab,jupyter/jupyterlab,eskirk/jupyterlab