Consistency problem when copying no-PK table

[yaqigithub]

Description When table has no primary key and src job copy data to half, pause the dtle and then restart dtle .The Dest data is different with Src

Steps to reproduce the issue: 1.create schema and table in Src and insert multiple data.Table has no primary key 2. create job 3.When data during the copying process，kill dtle 4.Then restart dtle and job 5.Compared Src and Dest data

Describe the results you received: Src data is same with Dest data

Describe the results you expected: Data is different in Src and Dset Output of ./dtle version:

(paste your output here)

Additional information you deem important (e.g. issue happens only occasionally):

Additional details (log, config, job config etc):