dsb_DE locale: Fix syntax error and add tests (bug 23208).

Fixed syntax error in the collation rules of Lower Sorbian language.
Collation test added in order to test the bugs like this early.

Reported-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>

	[BZ #23208]
	* localedata/Makefile (test-input): Add dsb_DE.UTF-8.
	(LOCALES): Likewise.
	* localedata/dsb_DE.UTF-8.in: New file.
	* localedata/locales/dsb_DE (LC_COLLATE): Fix syntax error.