fixed small bug in sourcescheck

no more false alarm in uggrid

[[Imported from SVN: r2173]]

am/sourcescheck

 # -*- Makefile -*-
 # $Id$
 
-sourcescheck_LIST = $(SOURCES) $(HEADERS) \
+sourcescheck_LIST = $(SOURCES) $(DIST_SOURCES) $(HEADERS) $(DIST_HEADERS) \
 	$(sourcescheck_NOSOURCES) $(dist_noinst_DATA)
 
 sourcescheck: sourcescheck-recursive