Fix runBatchedQuery.php for no result from select
Using a where without any result the script shows:
Notice: Undefined variable: end in maintenance\runBatchedQuery.php on
line 104
0 rows affected
Change-Id: Ib7839b9c5c3aabb2d70809b0a28cc62dd71678cd
(cherry picked from commit 4d6ce37028a048944d787df893e156212c2a1003)