fix startup bug in Firefox (fixes #1770) (#1780)
fix startup bug in Firefox (fixes #1770) (#1780)

* fix startup bug in Firefox (fixes #1770)

Co-authored-by: Godfrey Chan <0966a165cff09fd9b0dd27fd6a2242e2aeba351e@gmail.com>
emberjs/ember-inspector,emberjs/ember-inspector