Fix indentation of subforms inside letfn forms

Fixes: guns/vim-clojure-static#56
Related: guns/vim-clojure-static#83

Author: axvr

indent/clojure.vim

@@ -40,7 +40,7 @@ if exists("*searchpairpos")
 	endif
 
 	if !exists('g:clojure_special_indent_words')
-		let g:clojure_special_indent_words = 'deftype,defrecord,reify,proxy,extend-type,extend-protocol,letfn'
+		let g:clojure_special_indent_words = 'deftype,defrecord,reify,proxy,extend-type,extend-protocol'
 	endif
 
 	if !exists('g:clojure_align_multiline_strings')