Fix 2269 - use ktlint stdin.

Use stdin flag instead of temporary files. This allows ktlint to work
with .editorconfig files.

autoload/ale/fixers/ktlint.vim

@@ -3,7 +3,6 @@
 
 function! ale#fixers#ktlint#Fix(buffer) abort
     return {
-    \   'command': ale#handlers#ktlint#GetCommand(a:buffer) . ' --format',
-    \   'read_temporary_file': 1,
+    \   'command': ale#handlers#ktlint#GetCommand(a:buffer) . ' --format'
     \}
 endfunction

autoload/ale/handlers/ktlint.vim

@@ -13,7 +13,7 @@ function! ale#handlers#ktlint#GetCommand(buffer) abort
     return ale#Escape(l:executable)
     \   . (empty(l:options) ? '' : ' ' . l:options)
     \   . (empty(l:rulesets) ? '' : ' ' . l:rulesets)
-    \   . ' %t'
+    \   . ' --stdin'
 endfunction
 
 function! ale#handlers#ktlint#GetRulesets(buffer) abort