yes, that is the one that has been installed:
openhabian@openhabian:/usr/share/openhab/runtime/system/com/google/code/gson/gson $ ls -l
total 4
drwxr-xr-x 2 openhab openhab 4096 Dec 26 12:37 2.9.1
but for some reason it still requires 2.8.9 as seen in the logs