Add changelog for 17874

Author: cjjdespres

changes/17874.md

@@ -0,0 +1,11 @@
+This PR eliminates unnecessary genesis ledger rehashing when bootstrapping from
+genesis, speeding up that process by about 1.5 minutes directly, depending on
+hardware.
+
+This PR also fixes a related bug: the initial best tip network would formerly
+always fail on mainnet when bootstrapping from genesis, due to the daemon
+becoming unresponsive while rehashing the genesis ledger. This would delay
+startup by an additional number of minutes, cause the daemon to report itself as
+synced while its best tip was still at genesis until the next best tip query
+succeeded, and cause confusing behaviour in rosetta. This initial query should
+now only fail under very specific poor network conditions.