remove erroneous extra comma in "config.example.json"
remove erroneous extra comma in "config.example.json"

KeithHanson/screeps-typescript,Sean-Brown/screeps-typescript-starter,tinnvec/aints,Adirelle/typescreeps,Sean-Brown/screeps-typescript-starter,KeithHanson/screeps-typescript,boriswintein/Empire,bryanbecker/screeps-typescript-starter,bryanbecker/screeps-typescript-starter,Adirelle/typescreeps,tinnvec/aints