Chat window doesn't always notify the user on Windows

[jnodev]

One of my chat partners (Windows 7, Ricochet 1.0.4) complains, that the chat window sometimes doesn't blink after receiving new messages. I can reproduce the problem with a build from current master on Windows 8.1 with following steps:

• from windows start a chat to another system. Keep the chat window at front.
• send a reply from the other system. The taskbar on Windows starts blinking.
• wait until the blinking stops. You might exchange further messages.
• from now on the chat window on Windows won't blink until you minimize and restore it

Thus to minimize a chat window on Windows you have to minimize, restore, minimize.