accounting_ui_test: fix pylint issues

and re-enable coding style test
7 jobs for feat/accounting_ui_test_coding_style in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner1

00:51:22

failed ERP5.PerformanceTest-TestRunner1

00:32:22

failed ERP5.UnitTest-TestRunner1

01:18:17

canceled ERP5.UnitTest-TestRunner1

01:30:35

failed ERP5.UnitTest-TestRunner1

02:11:11

canceled ERP5.UnitTest-TestRunner1

canceled ERP5.UnitTest-TestRunner1

01:31:51