avconv fail because of a translation bug in french

The vokoscreen fails to produce the video output when the french locale is selected. Here is the application console log:

QString::arg: Argument missing: "% 1" , 1440
QString::arg: Argument missing: "% 1" , 900
[vokoscreen] ffmpegcommand : "avconv -f x11grab -r 25 -s % 1x% 1 -i :0.0+0,0 -pix_fmt yuv420p -vcodec mpeg4 -ar 48000 -qscale 1 -r 25 /tmp/vokoscreen-vokoscreen/vokoscreen-2014-06-16_23-09-17.mkv"

The string substitution fails because there is a space in the positional argument "% 1". The root of this problem is:

vokoscreen-1.9.0/language/vokoscreen_fr_FR.ts

   <message>
        <source>%1</source>
        <translation>% 1</translation>
    </message>