`po/Submakefile`:  hide giant `xgettext` command line
`po/Submakefile`:  hide giant `xgettext` command line

This command is retriggered upon edit of any number of source files.
It can be annoying, especially when changing a single file, and having
its build output obscured by this output.

strahlex/machinekit,strahlex/machinekit,strahlex/machinekit,strahlex/machinekit,strahlex/machinekit,strahlex/machinekit,strahlex/machinekit