Nextcloud-snap: Update nextcloud to 15.0.4

[pachulo]

[dutchievj]

https://nextcloud.com/blog/time-to-update-nextcloud-15.0.4-14.0.7-and-13.0.11-are-here/

Is this snap dead?

Currently running 15.0.2 stable on my snap install and its not patched up to 15.0.4 :-(

[gcollura]

@dutchievj I think they totally skipped 15.0.3.
Looking forward to this version to have the upload to s3 storage fixed.

[kyrofa]

Is this snap dead?

Haha, both 15.0.3 and 15.0.4 were both literally just released, a smidge of patience would be appreciated. This is not an automatic operation. You can use the 15/edge channel for that.

[kyrofa]

Help testing #890 would certainly be welcome (directions over there).