Removed a dangling comma in config.json
Removed a dangling comma in config.json

nickRm/xjava,FridaTveit/xjava,jmluy/xjava,nickRm/xjava,FridaTveit/xjava,jtigger/xjava,exercism/xjava,jtigger/xjava,jmluy/xjava,exercism/xjava