chainparams: Remove llmq_50_60 from regtest (#3696)
chainparams: Remove llmq_50_60 from regtest (#3696)

Its just not used anywhere so there is no point in starting the thread 
for it imo since it just spams the test logs with tries/failures.
dashpay/dash,dashpay/dash,dashpay/dash,UdjinM6/dash,UdjinM6/dash,thelazier/dash,UdjinM6/dash,thelazier/dash,UdjinM6/dash,thelazier/dash,thelazier/dash,dashpay/dash,UdjinM6/dash,thelazier/dash,dashpay/dash