message: fix scrollTo api bug
diff: @@ -551,6 +551,10 @@ export function coreMixin(BScroll) {
  }
  BScroll.prototype.scrollTo = function (x, y, time = 0, easing = ease.bounce) {
  + const isMoved = this.x !== x || this.y !== y
  + // an useless scroll
  + if (!isMoved) return
  +
  this.isInTransition = this.options.useTransition && time > 0 && (x !== this.x || y !== this.y)
  if (!time || this.options.useTransition) {
  @@ -561,8 +565,7 @@ export function coreMixin(BScroll) {
  if (time && this.options.probeType === PROBE_REALTIME) {
  this._startProbe()
  }
  -
  - if (!time && (x !== this.x || y !== this.y)) {
  + if (!time) {
  this.trigger('scroll', {
  x,
  y
  