config/Makefile.am: ensure getdate.sh is in dist tarball

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

config/Makefile.am

@@ -29,6 +29,7 @@ EXTRA_DIST = \
         ltmain_pgi_tp.diff \
         opal_mca_priority_sort.pl \
         find_common_syms \
+        getdate.sh \
         make_manpage.pl \
         md2nroff.pl