pytest: Reduce noise from bitcoind

I was hoping to trigger on more things from the bitcoind process, but
stuff like mempool is hard to trigger on. Reducing to info so we can
work a bit easier with pdb and the log becomes less noisy.

tests/utils.py

@@ -186,7 +186,6 @@ class BitcoinD(TailableProc):
             '-printtoconsole',
             '-server',
             '-regtest',
-            '-debug',
             '-logtimestamps',
             '-nolisten',
         ]