add missing space in exception message for plot_kde (#2054)
add missing space in exception message for plot_kde (#2054)

* added missing space in exception message for plot_kde

* Update arviz/plots/kdeplot.py

Co-authored-by: Oriol Abril-Pla <af72bf69da82104e3d3d691a18658247d02fe853@gmail.com>
arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz