Update copyright headers

benchmark/benchmark.go

cmd/benchmark.go

cmd/conf/db.go

cmd/conf/db_test.go

cmd/conf/gateways.go

cmd/conf/gateways_test.go

cmd/conf/graphgen.go

cmd/conf/graphgen_test.go

cmd/conf/metrics.go

cmd/conf/metrics_test.go

cmd/conf/node.go

cmd/conf/node_test.go

cmd/conf/params.go

cmd/conf/params_test.go

cmd/conf/paths.go

cmd/conf/paths_test.go

cmd/conf/permissioning.go

cmd/conf/permissioning_test.go

cmd/node.go

cmd/performance.go