[ruby/reline] Move only one line when render a line and then go to the next line

https://github.com/ruby/reline/commit/8a966cd962

lib/reline/line_editor.rb

@@ -1220,7 +1220,7 @@ class Reline::LineEditor
         height = render_partial(prompt, prompt_width, line, back, with_control: false)
       end
       if index < (@buffer_of_lines.size - 1)
-        move_cursor_down(height)
+        move_cursor_down(1)
         back += height
       end
     end

test/reline/yamatanooroti/test_rendering.rb

@@ -290,7 +290,6 @@ begin
     end
 
     def test_clear_multiline_and_autowrap
-      omit # FIXME clear logic is buggy
       start_terminal(10, 15, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl}, startup_message: 'Multiline REPL.')
       write("def aaaaaa\n  3\n\C-lend")
       close