trivial: Restore blank line in qapi-schema

Commit de63ab61 accidentally undid part of commit a43edcf2,
because the two patches were written in parallel, and the
blank line was not noticed as a casualty of merge conflicts.
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1476739794-19536-1-git-send-email-eblake@redhat.com>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

qapi-schema.json

@@ -737,6 +737,7 @@
             '*tls-hostname': 'str',
             '*max-bandwidth': 'int',
             '*downtime-limit': 'int'} }
+
 ##
 # @query-migrate-parameters
 #