Add server specification

core/src/rpc.rs

@@ -172,7 +172,7 @@ pub struct Meta {
 }
 impl Metadata for Meta {}
 
-#[rpc]
+#[rpc(server)]
 pub trait RpcSol {
     type Metadata;
 

core/src/rpc_pubsub.rs

@@ -13,7 +13,7 @@ use solana_sdk::signature::Signature;
 use std::mem;
 use std::sync::{atomic, Arc};
 
-#[rpc]
+#[rpc(server)]
 pub trait RpcSolPubSub {
     type Metadata;
 

vote-signer/src/rpc.rs

@@ -59,7 +59,7 @@ pub struct Meta {
 }
 impl Metadata for Meta {}
 
-#[rpc]
+#[rpc(server)]
 pub trait VoteSignerRpc {
     type Metadata;