Debian Multimedia :: Updating Icedove And Iceowl Extension

I'm using icedove with the calendar extension. Since quite some time there is a pending update from 31.7 to 31.8 which is held back by apt:

Code: Select all> apt --installed list icedove iceowl-extension
Listing... Done
icedove/testing,now 31.7.0-1 amd64 [installed,upgradable to: 31.8.0-1~deb8u1]
iceowl-extension/testing,now 31.7.0-1 amd64 [installed,upgradable to: 31.8.0-1~deb8u1]

> sudo apt upgrade
Reading package lists... Done
Building dependency tree       

[code]....

Seems like the problem lies with the package libvpx1. The correct version (>= 1.3) seems to be installed but under the name libvpx2.

Code: Select all> sudo apt install icedove

The following packages have unmet dependencies:

 icedove : Depends: libvpx1 (>= 1.3.0) but it is not installable
E: Unable to correct problems, you have held broken packages.

> apt list --installed | grep libvpx
libvpx2/testing,now 1.4.0-4 amd64 [installed,automatic]
>

What can be done, or should the dependency in the icedove package be updated?