fixed small typos in thread pools names

lag observer should be created only in case there are more than 1 upstreams exists

src/main/kotlin/io/emeraldpay/dshackle/GrpcServer.kt

@@ -66,7 +66,7 @@ open class GrpcServer(
             serverBuilder.addService(it)
         }
 
-        val pool = Executors.newFixedThreadPool(20, CustomizableThreadFactory("fixed-grpc-%d"))
+        val pool = Executors.newFixedThreadPool(20, CustomizableThreadFactory("fixed-grpc-"))
 
         serverBuilder.executor(
             if (mainConfig.monitoring.enableExtended)

src/main/kotlin/io/emeraldpay/dshackle/config/context/SchedulersConfig.kt

@@ -28,7 +28,7 @@ open class SchedulersConfig {
     }
 
     private fun makeScheduler(name: String, prefix: String, size: Int, monitoringConfig: MonitoringConfig): Scheduler {
-        val pool = Executors.newFixedThreadPool(size, CustomizableThreadFactory("$name-%d"))
+        val pool = Executors.newFixedThreadPool(size, CustomizableThreadFactory("$name-"))
 
         return Schedulers.fromExecutorService(
             if (monitoringConfig.enableExtended)

src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt

@@ -198,7 +198,7 @@ abstract class Multistream(
             }
             lagObserver?.stop()
             lagObserver = null
-            if (upstreams.isNotEmpty()) {
+            if (upstreams.size > 1) {
                 lagObserver = makeLagObserver()
             }
         }

src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumPosGrpcUpstream.kt

@@ -40,6 +40,7 @@ import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.emeraldpay.etherjar.domain.BlockHash
 import io.emeraldpay.etherjar.rpc.RpcException
+import io.grpc.ManagedChannel
 import org.reactivestreams.Publisher
 import org.slf4j.LoggerFactory
 import reactor.core.publisher.Flux
@@ -119,6 +120,7 @@ open class EthereumPosGrpcUpstream(
     }
 
     override fun stop() {
+
     }
 
     override fun update(conf: BlockchainOuterClass.DescribeChain) {