Increase timeouts for stale nodes and block downloads

[Bushstar]

Summary

• Bitcoin uses 10 minutes for nTargetSpacing where as DeFiChain uses 30 seconds making nodes and block downloads timeout quicker than they should.

Implications

• Storage

  • [ ] Database reindex required
  • [ ] Database reindex optional
  • [ ] Database reindex not required
  • [x] None

• Consensus

  • [ ] Network upgrade required
  • [ ] Includes backward compatible changes
  • [ ] Includes consensus workarounds
  • [ ] Includes consensus refactors
  • [x] None