F'up: kdenlive master ppa

[Harald Albrecht]

After I noticed that there's now a separate MLT+frei0r ppa 
https://launchpad.net/~kdenlive/+archive/ubuntu/mlt I was able to 
install Kdenlive from ppa master. But ... that simply crashes when 
trying to load my existing recent projects created with 17.12.0d. On the 
console I see three(!) attempts to create an image ... which fails, and 
then Kdenlive simply crashes.

Regards,
Harald