fix(deps): update module github.com/rs/cors to v1.8.3

Author: renovate[bot]

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/pelletier/go-toml v1.7.0 // indirect
 	github.com/philhofer/fwd v1.0.0 // indirect
 	github.com/pkg/errors v0.9.1
-	github.com/rs/cors v1.6.0
+	github.com/rs/cors v1.8.3
 	github.com/satori/go.uuid v1.2.0
 	github.com/sebest/xff v0.0.0-20160910043805-6c115e0ffa35
 	github.com/segmentio/backo-go v0.0.0-20200129164019-23eae7c10bd3 // indirect