Post update cache purge not working in Nginx-Helper 1.9.9

I just upgrade Nginx-Helper from 1.9.7 to 1.9.9 , after that when I update a post the cache purge doesn’t work anymore.

I use fastcgi cache, and it works fine in version 1.9.7

My wordpress permalink setting is /%category%/%postname%

Dig Into log file, I notice that in 1.9.7 it purged URL /%category%/%postname% , but in 1.9.9(and 1.9.8) it purge /%category%/%postname%/ (with trailing slash) so the purging url seems doesn’t work right.

I have the same problem, any solution?