kolab httpd lots of invalid timezone errors in logs

Hello,

I noticed there are a lot of the folloging errors in /var/log/messages:

May 22 12:30:15 mail httpd: (12:30:15) timezoneconverter.cpp(51):#011Guessed timezone and found:  "" 
May 22 12:30:15 mail httpd: (12:30:15) commonconversion.cpp(44):#011invalid timezone:  "Europe/Kiev" , assuming floating time

Note the first line has an empty string, and the second line has extra spaces 
around the "Europe/Kiev" string.. like there's a string trim missing somewhere?

Any thoughts about what's wrong? How do I get rid of the errors? I've
checked all the kolab/roundcube config files, and can't spot any missing
or broken configurations.. but it's of course possible something is wrong in the
config, as that specific instance is quite old and has been upgraded
through many versions of kolab. It's currently running Kolab:16 on CentOS7.

I noticed those errors seem to happen at around the same time when I open emails 
with calendar invitations in roundcube webmail.. I checked the .ics in question, 
and it has "FLE" as the timezone, not "Europe/Kiev", so probably parsing goes wrong somewhere.. 

.ics example:

BEGIN:VTIMEZONE
TZID:FLE Standard Time
BEGIN:STANDARD
DTSTART:16010101T040000
TZOFFSETFROM:+0300
TZOFFSETTO:+0200

Thoughts?


Thanks,

-- Pasi