fix: handle null in deepSync (#729)

Author: RyoNkmr

packages/devtools/client/components/StateEditor.vue

@@ -55,7 +55,7 @@ function deepSync(from: any, to: any) {
  for (const key in fromValue) {
  if (Array.isArray(fromValue[key]))
  to[key] = fromValue[key].slice()
- else if (typeof fromValue[key] === 'object')
+ else if (typeof fromValue[key] === 'object' && fromValue[key] !== null)
  deepSync(fromValue[key], to[key])
  else
  to[key] = fromValue[key]