message: Return when there are no edits
diff: @@ -31,6 +31,9 @@ export class BibtexFormatter {
  this.duplicatesDiagnostics.clear()
  this.extension.logger.addLogMessage('Start bibtex formatting on user request.')
  const edits = await this.formatDocument(doc, sort, align)
  + if (edits.length === 0) {
  + return
  + }
  const edit = new vscode.WorkspaceEdit()
  edits.forEach(e => {
  edit.replace(doc.uri, e.range, e.newText)
  