cups-filters: Update to 1.28.8

cups-filters: Update to 1.28.8

- Update from 1.28.7 to 1.28.8
- Update of rootfile not required
- Changelog
    CHANGES IN V1.28.8
	- libcupsfilters: Made check whether the driverless PPD to
	  generate should be a fax out PPD more reliable (Issue #343).
	- foomatic-rip: Options in the 5th command line argument of
	  the CUPS filter command line are separated only by white
	  space and not by comma, also make sure that an option "none"
	  is not considered a custom page size (Issue #348).
	- implicitclass: Raise timeout for cups-browsed's answer from
	  20s to 60s (Pull request #346).
	- libcupsfilters: In the PPD generator really give priority to
	  Apple Raster against PDF (Issue #331).

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>