remove unwanted field

Author: wileyj

docs/mining.md

@@ -13,9 +13,6 @@ seed = "YOUR PRIVATE KEY"
 #mock_mining = True
 
 [miner]
-# Time to spend on the first attempt to make a block, in milliseconds.
-# This can be small, so your node gets a block-commit into the Bitcoin mempool early.
-first_attempt_time_ms = 1000
 # Time to spend mining a Nakamoto block, in milliseconds.
 nakamoto_attempt_time_ms = 20000