SCP_PRIVKEY is loaded only when the extension is instanciated

[mmouchous-ledger]

SCP Private Key's value is loaded from host's environment variable SCP_PRIVKEY at startup of the extension.
If the user changes this value from the host environment variable it is not updated.

ledger-vscode-extension/src/taskProvider.ts

Line 228 in 5ba3ffc

private keyvarEnv: string = process.env.SCP_PRIVKEY as string;

It would be nice to be done in appLoadExec / appDeleteExec functions.