clock: fix build

#8
1 job for master in 2 minutes and 34 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #102869
build-ubuntu

00:02:34

 
Name Stage Failure
failed
build-ubuntu Build
make[4]: Leaving directory '/builds/GNOME/gnome-panel/gnome-panel/libpanel-applet-private'
make[3]: *** [Makefile:1552: 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:748: 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