hotkey fixes

terminus-core/src/services/hotkeys.service.ts

@@ -120,10 +120,12 @@ export class HotkeysService {
                 if (typeof value === 'string') {
                     value = [value]
                 }
+                if (value) {
                     value = value.map((item) => (typeof item === 'string') ? [item] : item)
                     keys[key] = value
                 }
             }
+        }
         return keys
     }