BackToTop visibility when component upon it is applied re-renders

[brindosch]

Software version

Quasar: 0.15.4
OS: - jsfiddle
Node: -
NPM: -
Browsers: Chrome (latest), Firefox (latest), IE
iOS: -
Android: -
Any other software related to your bug:

JsFiddle (for Quasar v0.15+ only)

https://jsfiddle.net/3y8sqkzf/10/

What did you get as the error?

When binding the color prop of q-btn to change the color on demand (while using back-to-top directive ) it forces the button to a visible state. When the button is already visible it's ok.
Please see fiddle, there are two color switch btns to play with.

What were you expecting?

No change in visbility while switching colors

What steps did you take, to get the error?

Click the switch color button while at the top of the page. (jfiddle)

Note: Amazing framework!

[rstoenescu]

Fix available in 0.15.5. Thanks for reporting.