fix: error on repeated reading static (#5957)

* Update static.go

* rm initial value of static

---------

Co-authored-by: Andy Hsu <i@nn.ci>

server/static/static.go

@@ -16,11 +16,11 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-var static fs.FS = public.Public
+var static fs.FS
 
 func initStatic() {
 	if conf.Conf.DistDir == "" {
-		dist, err := fs.Sub(static, "dist")
+		dist, err := fs.Sub(public.Public, "dist")
 		if err != nil {
 			utils.Log.Fatalf("failed to read dist dir")
 		}