Pass USER as envvar when relaunching valet using sudo. Fixes #904

[bramus]

This is a workaround to fix #904. Root cause is VSCode yielding the wrong output for logname when launched from the Dock / Spotlight / Finder (see microsoft/vscode#96463). This bug in VSCode prevents valet share from working properly, when invoked from VSCode's terminal.

This workaround makes valet share work properly again in that case: when relaunching valet using sudo it will take in the current$USER and pass it in as an environment variable. This (overridden) environment variable is then used when launching ngrok.