iOS "Be the first to add a reaction" Italian translation

In the translation file I saw:

```
"Be the first to add a reaction" = "Sii il primo ad aggiungere una reazione";
```

In English "first" has no gender, but "il primo" in Italian is masculine and thus incorrect for many of our users.

For a more inclusive message I propose something along the lines of "Sii la prima persona ad aggiungere una reazione" (be the first person to add a reaction)