fix(Sticky): disable styles when active is false

[layershifter]

Fixes #2082.

[codecov-io]

Codecov Report

Merging #2083 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2083      +/-   ##
==========================================
+ Coverage   99.76%   99.76%   +<.01%     
==========================================
  Files         149      149              
  Lines        2601     2602       +1     
==========================================
+ Hits         2595     2596       +1     
  Misses          6        6

Impacted Files	Coverage Δ
src/modules/Sticky/Sticky.js	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 65ce852...34c70ef. Read the comment docs.

[levithomason]

Released in semantic-ui-react@0.74.0