`fps_only` config resizes the label when FPS is 100 or 10

[zaps166]

When MANGOHUD_CONFIG is set to fps_only, the label resizes non-stop when FPS is 100 or 10 causing FPS counter to change position os screen when it's aligned to the right.

MangoHud version: 0.7.2.

Steps to reproduce the behavior

1. Execute: MANGOHUD=1 MANGOHUD_CONFIG=fps_only,position=top-right,fps_limit=10 vkcube.
2. Observe FPS counter.

Expected behavior Don't resize the label as long as FPS counter shows constant value.

Screenshots

https://github.com/flightlessmango/MangoHud/assets/6239090/7b35ae8a-718f-4aa0-9fe7-b947dfe2ff00