connector: check for nil on cancel

Signed-off-by: Sumner Evans <sumner.evans@automattic.com>

pkg/connector/loginphone.go

@@ -34,7 +34,9 @@ type PhoneLogin struct {
 var _ bridgev2.LoginProcessUserInput = (*PhoneLogin)(nil)
 
 func (p *PhoneLogin) Cancel() {
-	p.authClientCancel()
+	if p.authClientCancel != nil {
+		p.authClientCancel()
+	}
 }
 
 func (p *PhoneLogin) Start(ctx context.Context) (*bridgev2.LoginStep, error) {

pkg/connector/loginqr.go

@@ -40,7 +40,9 @@ var _ bridgev2.LoginProcessDisplayAndWait = (*QRLogin)(nil) // For showing QR co
 var _ bridgev2.LoginProcessUserInput = (*QRLogin)(nil)      // For asking for password
 
 func (q *QRLogin) Cancel() {
-	q.authClientCancel()
+	if q.authClientCancel != nil {
+		q.authClientCancel()
+	}
 }
 
 func (q *QRLogin) Start(ctx context.Context) (*bridgev2.LoginStep, error) {