Riot looks to me like I'm sending the same message twice

[giomfo]

Reported by several users:

"Riot iOS suddenly started displaying my messages as if I'd sent the same thing twice. Recipients said it looked like one message to them. I switched rooms and it didn't happen when sending a message to another room."

[giomfo]

Reproduced, fix is in progress

[jeangb]

Steps to reproduce:

1. Open a room with enough bubbles in it to be necessary to scroll up several times to see the first msg
2. Open room details
3. Hit the FILES tab
4. Go back in the room view, scroll up several times to load previous bubbles
5. Go back in rooms list
6. From the rooms list, open again the room
7. Post a message

Msg is duplicated

[giomfo]

Done, wait for testing

[jeangb]

Validated with 0.3.6 develop #1536