bug fix add related item with has_many through relation
bug fix add related item with has_many through relation

Signed-off-by: Francesc Esplugas <352bf3ec073356d71f47cfcff2e546760ec67027@gmail.com>

typus/typus,brainsome-de/typus,chiragshah/typus,baban/typus,wollzelle/typus,chiragshah/typus,readyfor/typus,burn-notice/typus,wollzelle/typus,typus/typus,readyfor/typus,thirdthing/typus,brainsome-de/typus,brainsome-de/typus,readyfor/typus,burn-notice/typus,thirdthing/typus,burn-notice/typus,wollzelle/typus,readyfor/typus,thirdthing/typus,wollzelle/typus,typus/typus,chiragshah/typus,baban/typus,burn-notice/typus,baban/typus,chiragshah/typus,thirdthing/typus,brainsome-de/typus,baban/typus,typus/typus