Update c/image after https://github.com/containers/image/pull/1816

... to work around some of the "unexpected EOF" failures.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/github.com/vbauerster/mpb/v8/priority_queue.go

@@ -0,0 +1,33 @@
+package mpb
+
+// A priorityQueue implements heap.Interface
+type priorityQueue []*Bar
+
+func (pq priorityQueue) Len() int { return len(pq) }
+
+func (pq priorityQueue) Less(i, j int) bool {
+	// less priority pops first
+	return pq[i].priority > pq[j].priority
+}
+
+func (pq priorityQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *priorityQueue) Push(x interface{}) {
+	s := *pq
+	bar := x.(*Bar)
+	bar.index = len(s)
+	s = append(s, bar)
+	*pq = s
+}
+
+func (pq *priorityQueue) Pop() interface{} {
+	s := *pq
+	*pq = s[0 : len(s)-1]
+	bar := s[len(s)-1]
+	bar.index = -1 // for safety
+	return bar
+}