move useful options to micro repo

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

options.go

@@ -3,7 +3,6 @@ package grpc
 import (
 	"context"
 	"crypto/tls"
-	"net"
 
 	"github.com/unistack-org/micro/v3/server"
 	"google.golang.org/grpc"
@@ -12,9 +11,7 @@ import (
 
 type codecsKey struct{}
 type grpcOptions struct{}
-type netListener struct{}
 type maxMsgSizeKey struct{}
-type maxConnKey struct{}
 type tlsAuth struct{}
 type reflectionKey struct{}
 
@@ -38,16 +35,6 @@ func AuthTLS(t *tls.Config) server.Option {
 	return setServerOption(tlsAuth{}, t)
 }
 
-// MaxConn specifies maximum number of max simultaneous connections to server
-func MaxConn(n int) server.Option {
-	return setServerOption(maxConnKey{}, n)
-}
-
-// Listener specifies the net.Listener to use instead of the default
-func Listener(l net.Listener) server.Option {
-	return setServerOption(netListener{}, l)
-}
-
 // Options to be used to configure gRPC options
 func Options(opts ...grpc.ServerOption) server.Option {
 	return setServerOption(grpcOptions{}, opts)