Fix (error "Lisp nesting exceeds `max-lisp-eval-depth'") which crashes correct indentation

[tonini]

It fixes #168

If you try to indent on a blank line, one line before the last blank line in the buffer the following error raises and crashes the indentation.

(error "Lisp nesting exceeds `max-lisp-eval-depth'") 

Example:

1 defmodule Application.Behavior do
2
3   def something(arg) do
4
5   end
6   -> try to indent here raises `(error "Lisp nesting exceeds `max-lisp-eval-depth'")`
7  

[tonini]

/cc @edubkendo