remove Service bounds on ServiceBuilder::service()

tower/src/builder/mod.rs

@@ -291,10 +291,9 @@ impl<L> ServiceBuilder<L> {
     }
 
     /// Wrap the service `S` with the layers.
-    pub fn service<S, Request>(self, service: S) -> L::Service
+    pub fn service<S>(self, service: S) -> L::Service
     where
         L: Layer<S>,
-        L::Service: Service<Request>,
     {
         self.layer.layer(service)
     }