Always close HTTP connections in the container updater.

This is needed on Pythons (e.g. PyPy) which do not use reference
counting.

Change-Id: Ib75a2e63bdd6b6bc726fb3dbf905d36f427aaf2f

swift/container/updater.py

@@ -296,3 +296,5 @@ class ContainerUpdater(Daemon):
                     self.logger.exception(
                         _('Exception with %(ip)s:%(port)s/%(device)s'), node)
                 return HTTP_INTERNAL_SERVER_ERROR
+            finally:
+                conn.close()