Allow headscale to start if oidc setup fails.

This commit makes headscale fall back to CLI authentication if oidc
fails to initialised and posts a warning to users.

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

app.go

@@ -193,7 +193,7 @@ func NewHeadscale(cfg *Config) (*Headscale, error) {
 	if cfg.OIDC.Issuer != "" {
 		err = app.initOIDC()
 		if err != nil {
-			return nil, err
+			log.Warn().Err(err).Msg("failed to set up OIDC provider, falling back to CLI based authentication")
 		}
 	}