Installer: Handle VM uninstall before it has had a time to boot

Change-Id: I615bc949b5054b301899b1e0b7eae94a98126e61
diff --git a/core/headscale/client.go b/core/headscale/client.go
index 159fffb..f4d0f51 100644
--- a/core/headscale/client.go
+++ b/core/headscale/client.go
@@ -111,7 +111,7 @@
 			return strconv.Itoa(n.Id), nil
 		}
 	}
-	return "", fmt.Errorf("not found")
+	return "", ErrorNotFound
 }
 
 func (c *client) getNodeAddresses(user, node string) ([]net.IP, error) {