Fix libedit a bit more and discourage from using it

README.adoc

@@ -47,6 +47,9 @@ Build dependencies: CMake, pkg-config, help2man,
 Runtime dependencies: libev, Jansson, cURL, openssl,
                       readline or libedit >= 2013-07-12,
 
+Avoid libedit if you can, in general it works but at the moment history is
+acting up and I have no clue about fixing it.
+
  $ git clone --recursive https://git.janouch.name/p/json-rpc-shell.git
  $ mkdir json-rpc-shell/build
  $ cd json-rpc-shell/build