[Rd] configure check might fail for texi2any on Solaris

[Gábor Csárdi]

This is R-patched, from 15th of July. I get:

configure:5117: found /opt/csw/bin/texi2any
configure:5129: result: /opt/csw/bin/texi2any
configure:5141: checking whether texi2any is at least 5.1
configure:5163: result:no

However:

/opt/csw/bin/texi2any --version
texi2any (GNU texinfo) 6.1

Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Does the configure check fail or am I missing something?

Thanks,
Gabor