doc: Fix outdated comments referring to ::ChainActive() #23258

1. 
   meshcollider commented at 1:41 AM on October 12, 2021: contributor

   After #21866 there are a few outdated comments referring to ::ChainActive(), which should instead refer to ChainstateManager::ActiveChain().

2. Fix outdated comments referring to ::ChainActive() a0efe529e4
3. meshcollider added the label Docs on Oct 12, 2021
4. fanquake requested review from dongcarl on Oct 12, 2021
5. 
   jamesob commented at 6:25 PM on October 19, 2021: member

   ACK https://github.com/bitcoin/bitcoin/pull/23258/commits/a0efe529e4fd053b890450413b9ca5e1bcd8f2c2

   Thanks @meshcollider!

6. fanquake merged this on Oct 20, 2021
7. fanquake closed this on Oct 20, 2021

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8. meshcollider deleted the branch on Oct 20, 2021
9. sidhujag referenced this in commit f3d19d61cf on Oct 20, 2021
10. Fabcien referenced this in commit b562de8831 on Jul 15, 2022
11. Fabcien referenced this in commit 1b30587576 on Jul 15, 2022
12. DrahtBot locked this on Oct 30, 2022

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