qmdb/sync/gaps: clamp checked_add to range.end instead of unwrap-panic

Signed-off-by: SAY-5 <SAY-5@users.noreply.github.com>

Author: SAY-5

storage/src/qmdb/sync/gaps.rs

@@ -40,15 +40,15 @@ pub fn find_next<'a, F: Family>(
     let mut fetched_ops_iter = fetched_operations
         .iter()
         .map(|(&start_loc, &operation_count)| {
-            let end_loc = start_loc.checked_add(operation_count).unwrap();
+            let end_loc = start_loc.checked_add(operation_count).unwrap_or(range.end);
             start_loc..end_loc
         })
         .peekable();
 
     let mut outstanding_reqs_iter = outstanding_requests
         .into_iter()
         .map(|&start_loc| {
-            let end_loc = start_loc.checked_add(fetch_batch_size.get()).unwrap();
+            let end_loc = start_loc.checked_add(fetch_batch_size.get()).unwrap_or(range.end);
             start_loc..end_loc
         })
         .peekable();