core: make Base_edit raise in case of wrong matrixbox keys

This should not happens, but if this happens we should not just return
in the middle of the loop, because this returned value is not used,
so we would just silently edit partially.
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:59:04

failed ERP5.PerformanceTest-Master

00:34:47

failed ERP5.UnitTest-Master

02:27:39

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:45

passed SlapOS.Eggs.UnitTest-Master.Python3

00:27:31

failed Wendelin.UnitTest-Master

00:34:25