Can modify a message even when the conversation is in read only

Hello! It seems that a message can be edited even when a discussion is finish and put in read only. The message get edited, but the time of edition is not updated. Maybe we should hide the edit button when a conversion is closed?

added Bug label

added UX label

changed milestone to %0.2: Essential functions ready & corrective feedback

Agreed. If it's easier to implement, I'm also OK with a time lock: no message editing is possible after X minutes post-submission. X could = 15 minutes, for instance.

closed with commit 749e39c9

mentioned in commit 749e39c9