Call length in seconds: set 0 if exceed limit without warning

[skull591]

When I use the app, I manually added a log entry, and mistakenly add a large length in seconds on callin. Then I found that the length is set to 0s. It's not like that it's possible in real life to have a call that long, but I think a warning should be shown to notice users.

App version: 3.11.15
Anroid version: 5.0
Device: Nexus_5X

Step to reproduce:

1. Manually add a log entry
2. In the length in seconds entry, enter a large number
3. Click add