Very tiny gap between 2nd and 3rd hotbar slot in HUD

Steps to Reproduce:

1. Go into Creative, Survival, or Adventure mode.
2. Look at the hotbar.

Observed Results:
The hotbar has a very tiny gap between the second and third slots.

Expected Results:
The hotbar has no gaps in it at all.

Screenshots/Videos attached: Yes

Additional Notes by Reporter: I am only able to reproduce this issue on PC (resolution is 1920x1080) when the GUI Scale Modifier setting is set to -1 and in windowed mode when the GUI Scale Modifier setting is set to 0.