Prevent fox mesh JSON warning

[darkwing]

Explanation: The fox mesh was displaying a console warning because its value was correctly undefined but the presence check wasn't properly coded to allow an undefined value.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[metamaskbot]

Builds ready [2147076]

• builds: chrome, firefox, opera
• build viz: Build System
• code coverage: Report
• storybook: Storybook
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3
  • content-script: 0
  • contentscript: contentscript
  • disable-console: disable-console
  • inpage: inpage
  • phishing-detect: phishing-detect
  • sentry-install: sentry-install
  • ui: 0, 1, 2, 3, 4, 5

Page Load Metrics (272 ± 20 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	50	331	226	70	34
		domContentLoaded	232	421	257	44	21
		load	247	430	272	42	20
		domInteractive	232	421	257	44	21

highlights:

storybook

• ui/components/ui/mascot/mascot.stories.js
• ui/pages/first-time-flow/end-of-flow/end-of-flow.stories.js
• ui/pages/first-time-flow/metametrics-opt-in/metametrics-opt-in.stories.js
• ui/pages/first-time-flow/select-action/select-action.stories.js
• ui/pages/first-time-flow/welcome/welcome.stories.js
• ui/pages/unlock-page/unlock-page.stories.js

[Gudahtt]

LGTM!

[kumavis]

e2e failure looks unrelated

[kumavis]

merged via admin access