[gnome-builder] rustup: use getattr() to access possible code attribute

[Christian Hergert <chergert src gnome org>]

commit b7eae4e745766bc8309a2c2ffb8aa0e319f5ac9c
Author: Christian Hergert <chergert redhat com>
Date:   Sun Mar 19 17:23:47 2017 -0700

    rustup: use getattr() to access possible code attribute

 plugins/rustup/rustup_plugin/__init__.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/rustup/rustup_plugin/__init__.py b/plugins/rustup/rustup_plugin/__init__.py
index 34718bc..c542e27 100644
--- a/plugins/rustup/rustup_plugin/__init__.py
+++ b/plugins/rustup/rustup_plugin/__init__.py
@@ -408,7 +408,7 @@ class RustupInstaller(Ide.Transfer):
                 data_stream.read_line_async(GLib.PRIORITY_DEFAULT, cancellable, self._read_line_cb, 
cancellable)
         except Exception as ex:
             # ignore cancelled error
-            if ex.code is not 19:
+            if getattr(ex, 'code') != Gio.IOErrorEnum.CANCELLED:
                 print('_read_line_cb', ex)
 
     def _wait_cb(self, sub_process, result, task):