Fix nuxt fails to restart if restarted after the server failed to start due to a context conflict

[Tofandel]

Fixes an edge case where server can be null during a restart

Logs:

web:dev:  ERROR  Cannot restart nuxt:  Cannot use 'in' operator to search for 'upgrade' in undefined                                                                                                                                 3:46:49 PM
web:dev:
web:dev:   at NuxtDevServer._load (/node_modules/nuxi/dist/chunks/dev2.mjs:1903:19)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Please upload report for BASE (main@fc8ad74). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
src/utils/dev.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##             main    #560   +/-   ##
======================================
  Coverage        ?   1.31%           
======================================
  Files           ?      44           
  Lines           ?    2813           
  Branches        ?      44           
======================================
  Hits            ?      37           
  Misses          ?    2734           
  Partials        ?      42           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.