fix build in bundle mode

added bunlde mode build to CI to prevent this from happening again
in the future

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/util/resources_embedded.go

@@ -19,6 +19,7 @@ package util
 
 import (
 	"html/template"
+	"os"
 
 	"github.com/drakkan/sftpgo/v2/internal/bundle"
 	"github.com/drakkan/sftpgo/v2/internal/logger"