fix: Installation stopped by "No default route found"

No need to check the default route if install binaries only.

Related issue: harvester/harvester#6306

Signed-off-by: Chris Chiu <chris.chiu@suse.com>
(cherry picked from commit 5b05ca3)

pkg/console/install_panels.go

@@ -2120,7 +2120,7 @@ func addInstallPanel(c *Console) error {
 				printToPanel(c.Gui, "Failed to check default route.", installPanel)
 				return
 			}
-			if !isDefaultRouteExist {
+			if !installModeOnly && !isDefaultRouteExist {
 				logrus.Error(ErrMsgNoDefaultRoute)
 				printToPanel(c.Gui, ErrMsgNoDefaultRoute, installPanel)
 				return