Observium tries to open munin graphs from the wrong path

Hi.

after updating observium to 23.9.13005 it seems to be the web interface tries to open the munin graphs from the wrong path.

the rrd's are saved under the hostname but the web interface tries to open it directly from the rrd path.

E.g.: 

real path: /opt/observium/rrd/10.242.0.9/munin_ping_10.242.0.10_ping.rrd

web interface tries to open: /opt/observium/rrd/munin_ping_10.242.0.10_ping.rrd

Error Messages says: No such file or directory.

How we can fix this issue?

BR. Torsten