erp5_configurator_standard_ui: Increase default activity wait timeout.

Consistently with the Selenium timeout increase.
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:07:14

failed ERP5.UnitTest-Master.Medusa

03:40:17

passed SlapOS.Eggs.UnitTest-Master.Python2

00:09:49

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:07