fix(finder): followup to #2442, make sure entry is not nil (#2526)

lua/telescope/finders/async_job_finder.lua

@@ -60,7 +60,9 @@ return function(opts)
     for line in stdout:iter(true) do
       line_num = line_num + 1
       local entry = entry_maker(line)
-      entry.index = line_num
+      if entry then
+        entry.index = line_num
+      end
       if process_result(entry) then
         return
       end

lua/telescope/finders/async_oneshot_finder.lua

@@ -71,7 +71,9 @@ return function(opts)
           end
 
           local entry = entry_maker(line)
-          entry.index = num_results
+          if entry then
+            entry.index = num_results
+          end
           results[num_results] = entry
           process_result(entry)
         end