message: add "px" as a fallback unit for custom column width
  Fixes
diff: @@ -141,7 +141,12 @@ function tweakClassesFromVisualSettings() {
  document.body.classList.add('btd__custom_column_size');
  const styleTag = document.createElement('style');
  - const safeValue = settings.custom_columns_width.size.replace(/;\{\}/g, '');
  + let safeValue = settings.custom_columns_width.size.replace(/;\{\}/g, '');
  +
  + if (!safeValue.includes('px') || !safeValue.includes('em') || !safeValue.includes('%') || !safeValue.includes('vw') || !safeValue.includes('vh') || !safeValue.includes('in') || !safeValue.includes('pt')) {
  + safeValue = `${safeValue}px`;
  + }
  +
  styleTag.type = 'text/css';
  styleTag.appendChild(document.createTextNode(`
  body.btd__custom_column_size .column {
  