Preserve phase when sampling 50 fps from a 60 fps camera

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoCadence.kt

@@ -9,7 +9,7 @@ internal class CallVideoCadence(private val fps: Int) {
         lastPts = pts
         val scaled = pts * fps
         if (next >= 0 && scaled < next - 250_000) return false
-        next = if (next < 0 || scaled - next > 250_000) scaled + 1_000_000 else next + 1_000_000
+        next = if (next < 0 || scaled - next > 1_000_000) scaled + 1_000_000 else next + 1_000_000
         return true
     }
 }