erp5_json_editor: make jslint happy

6 jobs for for_testrunner_2 in 0 seconds
Status Job ID Name Coverage
  External
canceled ERP5.CodingStyleTest-TestRunner2

02:34:50

canceled ERP5.UnitTest-TestRunner2

02:31:33

failed ERP5.CodingStyleTest-TestRunner2

07:49:45

failed ERP5.CodingStyleTest-TestRunner2

01:26:05

passed ERP5.UnitTest-TestRunner2

07:52:59

passed ERP5.UnitTest-TestRunner2

02:12:28