Check for python version to avoid converting target to bytes in python3

protoc-gen-twirp_python/main.go

@@ -79,6 +79,7 @@ func (g *generator) generateFile(file *descriptor.FileDescriptorProto) *plugin.C
 	g.P(`    from urllib.error import HTTPError`)
 	g.P(`import json`)
 	g.P(`from google.protobuf import symbol_database as _symbol_database`)
+	g.P(`import sys`)
 	g.P()
 	g.P(`_sym_db = _symbol_database.Default()`)
 	g.P()
@@ -134,7 +135,10 @@ func (g *generator) generateProtobufClient(file *descriptor.FileDescriptorProto,
 	g.P(`            server_address: The address of the server to send requests to, in`)
 	g.P(`                the full protocol://host:port form.`)
 	g.P(`        """`)
-	g.P(`        self.__target = server_address.encode('ascii')`)
+	g.P(`        if sys.version_info[0] > 2:`)
+	g.P(`            self.__target = server_address`)
+	g.P(`        else:`)
+	g.P(`            self.__target = server_address.encode('ascii')`)
 	g.P(`        self.__service_name = `, strconv.Quote(fullServiceName(file, service)))
 	g.P()
 	g.P(`    def __make_request(self, body, full_method):`)