Fixed "Warning" message that broke E04-5

Author: Xavier NUNN

ch04-logic-and-recursion.asciidoc

@@ -143,7 +143,7 @@ your +import+ as follows:
 ----
  import Kernel, except: [raise: 2, raise: 3]
 ----
-====
+=====
 
 <<SOLUTION04-ET04,See a suggested solution in Appendix A.>>