Current master branch points version 1.9.0, but the latest version of the plugin in wordpress plugin directory points 1.9.1
The 1.9.1 release was a cherry-picking of commits from master. Specifically, the v1.9.1 tag points to 369e94834769ec5ccf2ab7d5548c753fda1c2caf of the release/1.9.1 branch.
It may still be sensible to merge this commit to master.
Closing as this is a known issue and something that may change later but right now isn't an issue.
Most helpful comment
The 1.9.1 release was a cherry-picking of commits from master. Specifically, the v1.9.1 tag points to 369e94834769ec5ccf2ab7d5548c753fda1c2caf of the release/1.9.1 branch.
It may still be sensible to merge this commit to master.