Remaining work time notification duplicates itself

[SiekamCebule]

That bug appeared in one tested scenario:

• Session duration: 10 seconds
• Short breaks interval: 3 seconds

After ending the short break, the notification duplicated itself, so we have two ones:

• "Remaining time: 00:00:03"
• "Remaining time: X", where X is an actual time to the session end

An important observation is a fact, that after delaying short break the bug doesn't appear