remove blsct logs from debug.lg by default

[bocyaj]

I notice there are quite a lot of logs within debug.log in regards to the coin mixing process:

"
2021-03-02 06:59:49 blsctblindingkeypool return 15
2021-03-02 06:59:49 blsctblindingkeypool return 20
2021-03-02 06:59:49 blsctblindingkeypool return 23
2021-03-02 06:59:49 blsctblindingkeypool return 22
2021-03-02 06:59:49 blsctblindingkeypool return 16
2021-03-02 06:59:49 blsctblindingkeypool return 21
2021-03-02 06:59:49 blsctblindingkeypool return 17
2021-03-02 06:59:49 blsctblindingkeypool return 13
2021-03-02 06:59:49 blsctblindingkeypool return 19
2021-03-02 06:59:49 blsctblindingkeypool return 18
"

the debug.log gets pounded with these at times and wonder if they attribute to wallet performance.
seems I get about one for each xNAV input in my wallet every 3-5 seconds.

Do they have any debugging value?

I was thinking they could be surpressed unless a certain category of debug level is called for?

-debug=
Output debugging information (default: 0, supplying is optional). If is not supplied or if = 1, output all debugging information. can be: addrman, alert, bench, coindb, db, http, libevent, lock, mempool, mempoolrej, net, proxy, prune, rand, reindex, rpc, selectcoins, tor, zmq, qt.

maybe even create a new level of debug called 'blsct' ?

Thanks.

[aguycalled]

fixed in #809