handle exit properly in ugrid-shell.js
handle exit properly in ugrid-shell.js


Former-commit-id: fb18abdd1913f7075561edc6ec14934ee8a9bfc3
skale-me/skale-engine,mvertes/skale-engine,mvertes/skale-engine,skale-me/skale-engine,skale-me/skale-engine,mvertes/skale-engine