Fix the incorrect slashes denoting a default value in sum-of-multiples
Fix the incorrect slashes denoting a default value in sum-of-multiples

Egogre/xelixir,elasticdog/xelixir,cezarykosko/xelixir,wobh/xelixir,montague/xelixir,victorlcampos/xelixir,parkerl/xelixir,tjcelaya/xelixir,exercism/xelixir