Update `haskeline` library to latest HEAD

This is actually a no-op wrt the source-code and is only performed to show
that upstream is identical to our lagged repository.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

haskeline @ 0f23cdd3

-Subproject commit 708f0f604d8a9fea65a445892f262dfdf2a56ee6
+Subproject commit 0f23cdd341f0d72fc86e63198c6f48cbedbd3d16