default room avatar for an empty room should not be your own face

[ara4n]

if you create an empty room, it's unintuitive that the avatar is your own face. it should be unset

[morozkin]

@ara4n what should it be? In the web version user's avatar is used for an empty room avatar. Similar issue on the web version.

[ara4n]

i suggest using the text initial avatar, but with a space character as the initial so it's just a plain solid circle.