Prompt the last admin before letting them leave a room

[giomfo]

Currently the last admin is prompted like any other members

In Tchap, only the moderators and the admin are allowed to invite new members. And we want to prevent a room from being without admin. So in TchapV1, the following message was displayed when the end user was the last admin:

I request here to add the message: "Il ne sera plus administré..." as soon as the end user is the last admin even if the room join rule is public. We will keep the Element-Android message "Ce salon n'est pas public.... " in case of a private room, if the end user is not the last admin.
Note: We will keep the naming "salon" in the wording

I let you check in TchapV1 implementation how we detected the last admin

[Claire1817]

If last admin:
-> Private room -> "Ce salon ne sera plus administré....."
-> Public room -> "Ce salon ne sera plus administré....."
If not the last admin:
-> Private room -> "Ce salon n'est pas public....."
-> Public room -> ""

[giomfo]

Note: We will keep the naming "salon" in the wording

@ClaireGizard this remark concerns the first paragraph of the message too. I prefer switch back the wording on the Element one:
"Quitter le salon
Voulez vous vraiment quitter le salon?"

[giomfo]

ok