Fix uploader page request

app/src/main/java/com/hippo/ehviewer/client/data/ListUrlBuilder.java

@@ -577,7 +577,7 @@ public class ListUrlBuilder implements Cloneable, Parcelable {
                     // Empty
                 }
                 if (mNextGid != 0) {
-                    sb.append('/').append(mNextGid);
+                    sb.append("?next=").append(mNextGid);
                 }
                 return sb.toString();
             }