bug#28893: emacs-26.0.90 minor build issue on OpenIndiana

["Nelson H. F. Beebe" <beebe@math.utah.edu>]

Paul Eggert proposes a small patch to the emacs-26.0.90 configure
script to deal with the build problem that I reported for OpenIndiana.

I've just done a fresh build on that system, and Paul's patch solves
the problem:

	diff configure.~1~ configure
	17027c17027
	<   for tputs_library in '' tinfo ncurses terminfo termcap curses; do
	---
	>   for tputs_library in '' tinfo ncurses terminfo curses termcap; do

The build procedure went like this:

	set path= ( /bin /usr/bin /sbin /usr/sbin )

	env CONFIG_SITE= ./configure --prefix=$L --with-pop \
		--with-gnutls=no --with-gif=no && \
		gmake all check

	... long output omitted...

	% ./src/emacs --version | head -1
	GNU Emacs 26.0.90

I suggest, however, that configure.ac acquire some explanatory
comments to document why -lcurses should be searched before -ltermcap
on OpenIndiana.

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
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