Makefile: Do not preserve ownership

If we use cp -a files might copied with the wrong ownership and might end up like this on the target iso.

Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

Makefile

@@ -24,7 +24,7 @@ install-initcpio:
 
 install-examples:
 	install -d -m 755 $(DESTDIR)/usr/share/archiso/
-	cp -a configs $(DESTDIR)/usr/share/archiso/
+	cp -a --no-preserve=ownership configs $(DESTDIR)/usr/share/archiso/
 
 install-doc:
 	install -D -m 644 README $(DESTDIR)/usr/share/doc/archiso/README