Update protobuf_deps.bzl

protobuf_deps.bzl

@@ -27,7 +27,6 @@ def protobuf_deps():
             name = "six",
             build_file = "@com_google_protobuf//:third_party/six.BUILD",
             sha256 = "d16a0141ec1a18405cd4ce8b4613101da75da0e9a7aec5bdd4fa804d0e0eba73",
-            strip_prefix = "six-1.12.0",
             urls = ["https://pypi.python.org/packages/source/s/six/six-1.12.0.tar.gz"],
         )