Changed board call times

Hello,

in its meeting on June 24, the board has agreed on the following new board call times:

The board calls will be held 90 minutes earlier every other meeting.

This means:
* We had a call at 17:00 Berlin time (right now 15:00 UTC) on June 24, calendar week 26.
* No call in calendar week 27, this week.
* A call at 15:30 Berlin time (right now 13:30 UTC) on July 8, calendar week 28.
* No call the week thereafter, calendar week 29.
* A call at 17:00 Berlin time (right now 15:00 UTC) on July 22, calendar week 30.
* And then the cycle starts again.

As usual, you can find all the details on https://wiki.documentfoundation.org/TDF/BoD_Meetings

Florian