message: doc: Clarify nPruneAfterHeight for signet
diff: @@ -82,7 +82,7 @@ private:
  *
  * Pruning functions are called from FlushStateToDisk when the global fCheckForPruning flag has been set.
  * Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.)
  - * Pruning cannot take place until the longest chain is at least a certain length (100000 on mainnet, 1000 on testnet, 1000 on regtest).
  + * Pruning cannot take place until the longest chain is at least a certain length (CChainParams::nPruneAfterHeight).
  * Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip.
  * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files.
  * A db flag records the fact that at least some block files have been pruned.
  