ITS#7432 fix typo in mdb_midl_sort

Wasn't pushing the optimal half of the array onto the stack,
thus used more stack than expected -> overrun.

libraries/libmdb/midl.c

@@ -232,7 +232,7 @@ mdb_midl_sort( MDB_IDL ids )
 			ids[l+1] = ids[j];
 			ids[j] = a;
 			jstack += 2;
-			if (ir-i+1 >= j-1) {
+			if (ir-i+1 >= j-l) {
 				istack[jstack] = ir;
 				istack[jstack-1] = i;
 				ir = j-1;