Replay video from start when play is pressed at end

Closes #510

Tusker/Screens/Gallery/VideoOverlayViewController.swift

@@ -106,6 +106,9 @@ class VideoOverlayViewController: UIViewController {
         if player.rate > 0 {
             player.rate = 0
         } else {
+            if player.currentTime() >= player.currentItem!.duration {
+                player.seek(to: .zero)
+            }
             #if os(visionOS)
             player.play()
             #else