Update Serbian translation

(cherry picked from commit 62594d07)
1 job from master in 4 minutes and 41 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
failed #242210
build-ubuntu

00:04:41

 
Name Stage Failure
failed
build-ubuntu Build
make[4]: Leaving directory '/builds/GNOME/gnome-panel/gnome-panel'
make[3]: *** [Makefile:1344: all-recursive] Error 1
make[3]: Leaving directory '/builds/GNOME/gnome-panel/gnome-panel'
make[2]: Leaving directory '/builds/GNOME/gnome-panel/gnome-panel'
make[2]: *** [Makefile:679: all] Error 2
make[1]: *** [Makefile:540: all-recursive] Error 1
make[1]: Leaving directory '/builds/GNOME/gnome-panel'
make: *** [Makefile:472: all] Error 2
ERROR: Job failed: exit code 1