Update module gorilla/handlers to v1.5.1

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/go-ldap/ldap/v3 v3.2.4
 	github.com/gofrs/flock v0.8.0 // indirect
 	github.com/google/go-cmp v0.4.0
-	github.com/gorilla/handlers v1.4.2
+	github.com/gorilla/handlers v1.5.1
 	github.com/lunixbochs/struc v0.0.0-20200707160740-784aaebc1d40
 	github.com/miscreant/miscreant.go v0.0.0-20200214223636-26d376326b75
 	github.com/openzipkin/zipkin-go v0.2.2