During installation, don't unconditionally create an empty `modules-old' directory.

Makefile.in

@@ -46,6 +46,7 @@ CFLAGS		= @CFLAGS@
 # the system one.
 #CFLAGS= -DNDEBUG -g -O2 -D"FD_SETSIZE=1024"
 SHELL=/bin/sh
+# `extensions' must be after `modules' for proper creation of $(moduledir).
 SUBDIRS=libratbox modules extensions src tools ssld bandb doc help
 CLEANDIRS = ${SUBDIRS}
 RSA_FILES=rsa_respond/README rsa_respond/respond.c rsa_respond/Makefile
@@ -128,9 +129,6 @@ install-mkdirs:
 	-@if test ! -d $(DESTDIR)$(mandir); then \
 		mkdir $(DESTDIR)$(mandir); \
 	fi
-	-@if test ! -d $(DESTDIR)$(moduledir); then \
-		mkdir $(DESTDIR)$(moduledir); \
-	fi
 	-@if test ! -d $(DESTDIR)$(helpdir); then \
 		mkdir $(DESTDIR)$(helpdir); \
 	fi

modules/Makefile.in

@@ -152,9 +152,6 @@ libmodules.a: $(S_OBJS) static_modules.o
 
 install-mkdirs:
 	@echo "ircd: setting up modular directory structure"
-	-@if test ! -d $(DESTDIR)$(moduledir); then \
-                mkdir $(DESTDIR)$(moduledir); \
-        fi
 	-@if test -d $(DESTDIR)$(moduledir)-old; then \
 		rm -rf $(DESTDIR)$(moduledir)-old; \
 	fi