[PATCH] Fix AC_CHECK_HEADERS for term.h to look in ncurses directory.

When ncurses headers are installed inside a subdirectory, the term.h
file will be there too.
---
While taking a closer look at the "mutt on macOS and --with-curses=DIR"
thread, I realized the configure.ac was actually making a mistake
searching for term.h.  It should be trying to look in the appropriate
ncurses subdirectory first, as it does for ncurses.h.

 configure.ac  |  4 ++--
 curs_ti_lib.c | 12 ++++++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index 36564a7b..fe84cfdd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -346,18 +346,18 @@ main ()
 
                   AC_CHECK_HEADERS(ncursesw/ncurses.h,[cf_cv_ncurses_header="ncursesw/ncurses.h"],
                     [AC_CHECK_HEADERS(ncurses.h,[cf_cv_ncurses_header="ncurses.h"])])
+                  AC_CHECK_HEADERS(ncursesw/term.h,,[AC_CHECK_HEADERS(term.h)])
                 else
                   AC_CHECK_LIB(tinfo, tgetent, [MUTTLIBS="$MUTTLIBS -ltinfo"])
 
                   AC_CHECK_HEADERS(ncurses/ncurses.h,[cf_cv_ncurses_header="ncurses/ncurses.h"],
                     [AC_CHECK_HEADERS(ncurses.h,[cf_cv_ncurses_header="ncurses.h"])])
+                  AC_CHECK_HEADERS(ncurses/term.h,,[AC_CHECK_HEADERS(term.h)])
                 fi],
 
                 [CF_CURSES_LIBS])
                 ])
 
-        AC_CHECK_HEADERS(term.h)
-
         old_LIBS="$LIBS"
         LIBS="$LIBS $MUTTLIBS"
         CF_CHECK_FUNCDECLS([#include <${cf_cv_ncurses_header-curses.h}>],
diff --git a/curs_ti_lib.c b/curs_ti_lib.c
index 3bb27155..c25161c6 100644
--- a/curs_ti_lib.c
+++ b/curs_ti_lib.c
@@ -28,8 +28,16 @@
  *       file than everywhere that includes mutt_curses.h.
  */
 
-#if !defined(USE_SLANG_CURSES) && defined(HAVE_TERM_H)
-#include <term.h>
+#if !defined(USE_SLANG_CURSES) && \
+  (defined(HAVE_TERM_H) || defined(HAVE_NCURSESW_TERM_H) || defined(HAVE_NCURSES_TERM_H))
+
+#if defined(HAVE_NCURSESW_TERM_H)
+  #include <ncursesw/term.h>
+#elif defined(HAVE_NCURSES_TERM_H)
+  #include <ncurses/term.h>
+#else
+  #include <term.h>
+#endif
 
 const char *mutt_tigetstr(const char *capname)
 {
-- 
2.53.0