Update OIDC callback URL in SSO documentation

[0nano]

Update the redirect URL in the documentation to reflect the actual redirect URI that was actually given to OIDC.

headplane/app/routes/auth/oidc-start.ts

Lines 51 to 69 in 985d7d9

	function getRedirectUri(config: HeadplaneConfig, req: Request): string {
	if (config.server.base_url != null) {
	const url = new URL(`${__PREFIX__}/oidc/callback`, config.server.base_url);
	return url.href;
	}
	if (config.oidc?.redirect_uri != null) {
	const url = new URL(
	`${__PREFIX__}/oidc/callback`,
	config.oidc.redirect_uri,
	);
	return url.href;
	}
	const url = new URL(`${__PREFIX__}/oidc/callback`, req.url);
	let host = req.headers.get('Host');
	if (!host) {
	host = req.headers.get('X-Forwarded-Host');
	}