Dismiss the notification without triggering default action on right-click

[danimateo]

This is an improvement to the problem presented by @BarbUk 's comment here: #3863 (comment)

On right click, the notification dismisses without triggering the default action. On left click, behavior is the same as until now.

[actionless]

thanks for looking into this!

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 91.27%. Comparing base (8b1f895) to head (01b0652).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3906   +/-   ##
=======================================
  Coverage   91.27%   91.27%           
=======================================
  Files         935      935           
  Lines       60129    60130    +1     
=======================================
+ Hits        54880    54883    +3     
+ Misses       5249     5247    -2     

Flag	Coverage Δ
gcov	91.27% <50.00%> (+<0.01%)	⬆️
luacov	93.90% <50.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
lib/naughty/layout/box.lua	94.19% <50.00%> (+0.03%)	⬆️

... and 2 files with indirect coverage changes