[BUG] Nul timeout allowed

[PaTara43]

1. Development/Production
dev.robonomics.app

2. Page Address
/rws-setup

3. Error Info/Story
When for some reason setting no timeout in the setting it allows saving and downloads invalid config file which results in integration setup fail

4. Expected behavior
Don't allow to save settings

5. Console logs

6. Context
Browser: Chrome
Dapp release: 421bcb7