fixed typo when accessing the metadata dict

Change-Id: I3fafb2e6670e0ef3ce18d2f0f03dfa1a2939e36d
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1092075
Signed-off-by: Jiri Moskovcak <jmoskovc@redhat.com>