Get dsos working again by including $(LTFLAGS) on the command-line for

the --mode=link invocations of libtool/shlibtool.  The lack of LTFLAGS
resulted in no -export-dynamic, and dsos couldn't resolve symbols in
httpd.

LTFLAGS was lost in the 1.23 revision of rules.mk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85956 13f79535-47bb-0310-9956-ffa450edef68