* Shrinks ubuntu.svg
Uses 1 circle with stroke for main ring instead
of 2 separate circles.
Simplifies path.
* Changes fill in outer circle to none
Based on @Erwan-le-Gall improvement in #490 , this
commit changes the fill in the large `circle` from
the same color as the containing `rect` to `none`,
shaving off 3 bytes.
f407f7686f