bee printconfig stderr, block-time, and bootnode

[Cafe137]

Context

Bee 2.3.0

Summary

I often deploy Bee nodes by creating the full YAML with the printconfig command, then adjust the values. I noticed some anomalies which I would like to report - if these are done on purpose, please just close the issue.

Expected behavior

• Is there a reason that printconfig writes to stderr instead of stdout? Needs to be used as ./bee printconfig &> bee.yaml.
• block-time: 15 is by default - maybe change it to 5 so if accidentally left unchanged, batchTTL values don't report over-exaggerated values?
• bootnode: [] is by default - maybe add "/dnsaddr/mainnet.ethswarm.org" so Bee can start connecting to other nodes?

Actual behavior

block-time: 15
bootnode: []

Steps to reproduce

./bee printconfig