Description of problem:
If the amount of users is higher then 250 (?), opening list of users (button with number of users in the right upper corner) crash Polari.

Version-Release number of selected component (if applicable):
polari-3.22.1-2.fc25.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Open Polari
2. Connect to the room with number of users above 250 (#fedora, #fedora-admin)
3. Click on the button showing number of users (right upper corner)
4. Polari crashes

Actual results:
Cannot browse list of users

Expected results:
Can open the user list like it's done with lower number

Additional info:
-I am running on Wayland
-This is error log from journal when the crash happen:


Nov 11 11:51:43 infinity org.gnome.Shell.desktop[12030]: Window manager warning: Could not import pending buffer, ignoring commit: Failed to create texture 2d due to size/format constraints
Nov 11 11:51:43 infinity unknown[14122]: Error 71 (Protocol error) dispatching to Wayland display.
Nov 11 11:51:43 infinity dbus-daemon[1471]: [session uid=1000 pid=1471] Activating service name='org.freedesktop.Telepathy.Client.Polari' requested by ':1.20' (uid=1000 pid=1619 comm="/usr/libexec/mission-control-5 " label="unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023")