Fix maxuploadtarget.py (#1220)
Fix maxuploadtarget.py (#1220)

Ever since the May152018 hardfork the minimum EB is set to 32MB, but
for this test to run in a reasonable amount of time we need to
set the EB to 1MB and also lower the mining block size as well.
Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited