Drop duplicate frequency in TrainrunSectionViewObject.generateKey()

Further down, these two calls return the same values:

    this.getTrainrun().getTrainrunFrequency().frequency
    this.getTrainrun().getTrainrunFrequency().offset

Signed-off-by: Simon Ser <[email protected]>

Author: emersion

src/app/view/editor-main-view/data-views/trainrunSectionViewObject.ts

@@ -88,10 +88,6 @@ export class TrainrunSectionViewObject {
       "_" +
       firstSection.getNumberOfStops() +
       "_" +
-      firstSection.getFrequency() +
-      "_" +
-      firstSection.getFrequencyOffset() +
-      "_" +
       this.getTrainrun().getTrainrunCategory().shortName +
       "_" +
       this.getTrainrun().getTrainrunFrequency().shortName +