message: Removed "popup" option from detailPanel property
diff: @@ -1867,7 +1867,7 @@ export class QuestionMatrixDropdownModelBase
  return this.columnLayout != "vertical";
  }
  /**
  - * Set the value to "underRow" to show the detailPanel under the row. Set the value to "popup" to show the detailPanel in the popup.
  + * Set the value to "underRow" to show the detailPanel under the row.
  */
  public get detailPanelMode(): string {
  return this.getPropertyValue("detailPanelMode", "none");
  @@ -3033,7 +3033,7 @@ Serializer.addClass(
  },
  {
  name: "detailPanelMode",
  - choices: ["none", "underRow", "underRowSingle", "popup"],
  + choices: ["none", "underRow", "underRowSingle"],
  default: "none",
  },
  "horizontalScroll:boolean",
  