fix filemeta

ecstore/src/file_meta.rs

@@ -606,6 +606,7 @@ impl FileMeta {
             versions.push(fi);
         }
 
+        let num = versions.len();
         let mut prev_mod_time = None;
         for (i, fi) in versions.iter_mut().enumerate() {
             if i == 0 {
@@ -613,6 +614,7 @@ impl FileMeta {
             } else {
                 fi.successor_mod_time = prev_mod_time;
             }
+            fi.num_versions = num;
             prev_mod_time = fi.mod_time;
         }