fix(deps): update module github.com/gorilla/mux to v1.8.1

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/bwmarrin/snowflake v0.3.0
 	github.com/envoyproxy/go-control-plane v0.9.9
 	github.com/golang/protobuf v1.5.0
-	github.com/gorilla/mux v1.8.0
+	github.com/gorilla/mux v1.8.1
 	github.com/huandu/xstrings v1.3.2 // indirect
 	github.com/imdario/mergo v0.3.11 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect

go.sum

@@ -281,6 +281,8 @@ github.com/googleapis/gnostic v0.4.1 h1:DLJCy1n/vrD4HPjOvYcT8aYQXpPIzoRZONaYwyyc
 github.com/googleapis/gnostic v0.4.1/go.mod h1:LRhVm6pbyptWbWbuZ38d1eyptfvIytN3ir6b65WBswg=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
+github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
 github.com/gorilla/websocket v0.0.0-20170926233335-4201258b820c/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7/go.mod h1:FecbI9+v66THATjSRHfNgh1IVFe/9kFxbXtjV0ctIMA=