Fix symlink to currency.units.
--- Makefile.in.orig	2022-09-04 21:00:06.000000000 -0500
+++ Makefile.in	2023-08-30 21:50:30.000000000 -0500
@@ -115,7 +115,7 @@
 	$(INSTALL_DATA) $(srcdir)/definitions.units $(DESTDIR)@UDAT@definitions.units
 	-rm -f $(DESTDIR)@UDAT@currency.units
 	$(INSTALL_DATA) $(srcdir)/currency.units $(DESTDIR)@CDAT@currency.units
-	if [ $(DESTDIR)@CDAT@ != $(DESTDIR)@UDAT@ ];then ln -sf $(DESTDIR)@CDAT@currency.units $(DESTDIR)@UDAT@currency.units;fi
+	[ @CDAT@ != @UDAT@ ] && ln -sf @CDAT@currency.units $(DESTDIR)@UDAT@currency.units
 	$(INSTALL_DATA) $(srcdir)/locale_map.txt $(DESTDIR)@UDAT@locale_map.txt
 	if test $(HAVE_PYTHON) = yes; then \
 	  $(INSTALL_PROGRAM) units_cur_inst $(DESTDIR)$(bindir)/`echo units_cur|sed '$(transform)'`;fi