[BUG] Fix unblock action

- At some point the unblock button was transformed into being handled by
Javascript, however the endpoint didn't yet respond in JSON.
- Ref: https://codeberg.org/kita/.profile/raw/branch/main/img/G94IqS9.png

(cherry picked from commit a3f1249f0a)

routers/web/user/profile.go

@@ -358,6 +358,7 @@ func Action(ctx *context.Context) {
 		redirectViaJSON = true
 	case "unblock":
 		err = user_model.UnblockUser(ctx, ctx.Doer.ID, ctx.ContextUser.ID)
+		redirectViaJSON = true
 	}
 
 	if err != nil {