If we do some resource action(e.g. create/update/delete ...),
UpdateRow will be started.
And then resource status will be updated automatically in front-end.
But in case removing resource, number of resource that displayed
on both above and bottom of table will not be updated correctly.
I fixed update_footer_count function in horizon.tables.js.
This function only updates number of resource in footer field.
(tfoot span.table_count)
But we also need to update header field. (thead span.table_count)
So I add header update logic into this file.
Change-Id: Idc4330fe779b62607ada39a9db3637de82d014f7
Closes-Bug: #1694207
(cherry picked from commit 5b2fe409ed)