typos in rest.j2
typos in rest.j2

1. duplicate "first" when list the aggregation method 
2. typo "retrived" to retrieved

Change-Id: I13d5f409d0cef67324f0b347d971d2ea9d8a2304

sileht/gnocchi,leandroreox/gnocchi,leandroreox/gnocchi,gnocchixyz/gnocchi,gnocchixyz/gnocchi,sileht/gnocchi