fix docker build KIKIMR-14588

ref:e1d9620600e1c895e309f7603d87129fcd41c704

ydb/public/tools/lib/cmds/__init__.py

@@ -343,7 +343,7 @@ def deploy(arguments):
     recipe.write_database(cluster.domain_name)
     recipe.write_connection_string(("grpcs://" if enable_tls() else "grpc://") + endpoint + "?database=/" + cluster.domain_name)
     if enable_tls():
-        recipe.write_certificates_path(configuration.grpc_tls_ca())
+        recipe.write_certificates_path(configuration.grpc_tls_ca.decode("utf-8"))
     return endpoint, database