Frame timing on gifs is one frame early

[omgitsraven]

Steps to reproduce

1. Look at the following gif in your browser: https://ravenworks.ca/temp/timingtest.gif
2. Note that "1" and "5" stay on screen for longer
3. Drag the gif into telegram, to send it "in a quick way"
4. Look at the animation in telegram; it will likely show the numbers "4" and "8" for longer instead! (Sometimes it displays correctly at first, until you've clicked to zoom in, and then it will be broken from then on.)

Expected behaviour

The frames that are set to display for longer should display for longer.

Actual behaviour

The frame BEFORE the frame that is meant to show for longer, shows for longer instead.

Operating system

Windows 10, 19045

Version of Telegram Desktop

5.4.1

Installation source

Static binary from official website

Crash ID

No response

Logs

No response

[LWChris]

Still confirmed in version 5.5.4.

Two notes:

1. Dragging the GIF from the browser into Telegram sent a png, I had to save the GIF on my computer to send it.
2. The animation is correct in the preview while attaching, and breaks once it was sent.