[ruby/reline] Fix autocomplete dialog width

https://github.com/ruby/reline/commit/9868432687

lib/reline/line_editor.rb

@@ -605,7 +605,11 @@ class Reline::LineEditor
       return
     end
     old_dialog = dialog.clone
-    dialog.width = dialog_render_info.width if dialog_render_info.width
+    if dialog_render_info.width
+      dialog.width = dialog_render_info.width
+    else
+      dialog.width = dialog_render_info.contents.map { |l| calculate_width(l, true) }.max
+    end
     height = dialog_render_info.height || DIALOG_HEIGHT
     pointer = dialog_render_info.pointer
     dialog.contents = dialog_render_info.contents