component/ncurses: markup versioned symbols using ld

to avoid possible "no version information available" warnings.

component/ncurses/buildout.cfg

@@ -14,6 +14,7 @@ configure-options =
   --with-pkg-config-libdir=%(location)s/lib/pkgconfig
   --with-shared
   --with-termlib
+  --with-versioned-syms
   --without-ada
   --without-manpages
   --without-tests