json-rpc server should always use local rpc client

Closes: #987
Solution:
- use local rpc clint if json-rpc is enabled.

CHANGELOG.md

@@ -49,6 +49,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Improvements
 
 - (rpc) [tharsis#979](https://github.com/tharsis/ethermint/pull/979) Add configurable timeouts to http server
+- (rpc) [tharsis#988](https://github.com/tharsis/ethermint/pull/988) json-rpc server always use local rpc client
 
 ## [v0.10.1] - 2022-03-04
 

server/start.go

@@ -318,9 +318,9 @@ func startInProcess(ctx *server.Context, clientCtx client.Context, appCreator ty
 	}
 
 	// Add the tx service to the gRPC router. We only need to register this
-	// service if API or gRPC is enabled, and avoid doing so in the general
+	// service if API or gRPC or JSONRPC is enabled, and avoid doing so in the general
 	// case, because it spawns a new local tendermint RPC client.
-	if config.API.Enable || config.GRPC.Enable {
+	if config.API.Enable || config.GRPC.Enable || config.JSONRPC.Enable {
 		clientCtx = clientCtx.WithClient(local.New(tmNode))
 
 		app.RegisterTxService(clientCtx)