Improve default_dbg to strip debug info from all binaries
@psykose aports!36878 (comment 250640)
Not clear why
Size difference for php81-apache2: 22 MiB -> 5416 KiB
it had failed to have the debug split before, so was never stripped. i don't know why as -dbg was the first subpackage (always should be), probably an abuild bug for the default_dbg split