frontend: Tag multiple items broken

[bodik]

request tag field empty, happens in review1 workbranch

-----------------------------47688292035021840031329642
Content-Disposition: form-data; name="tag"

-----------------------------47688292035021840031329642
Content-Disposition: form-data; name="action"

set
-----------------------------47688292035021840031329642
Content-Disposition: form-data; name="ids-0"

2
-----------------------------47688292035021840031329642
Content-Disposition: form-data; name="ids-1"

1
-----------------------------47688292035021840031329642
Content-Disposition: form-data; name="ids-2"

3
-----------------------------47688292035021840031329642--

[bodik]

likely a temporary refactoring bug, does not happen anymore