fix test

test/RewardsBooster_migration.test.ts

@@ -683,7 +683,7 @@ describe('RewardsBooster Contract', () => {
             // 3 block passed (upgrade, migrateDeploymentBoost, collectAllocationReward) since we queried alReward0,
             // and 1 of them counts on old rewards, so we should get 500.5 SQT * 103 (availabe secs) / 1003 (total secs) = 51.397308075772681954
             // sometimes the test takes longer than 3 sec for 3 blocks, so result may become 52291
-            expect(evts[0].amount.div((1e15).toString()).toString()).to.be.within(51397, 52291);
+            expect(evts[0].amount.div((1e15).toString()).toNumber()).to.be.within(51397, 52291);
             // 1 block(collectAllocationReward) passed for new reward pool, so we should get 1.25 SQT more
             expect(evts[1].amount).to.lt(etherParse('1.25'));
             await blockTravel(999);