bitcoin test in full test suite needs updating to zclassic values

[hairetikos]

me and @mountaindrifter have ironed out the issues to do with CheckSignature(alertKey), i have removed / edited a lot of code to do with the sendalert & key system (reference: https://github.com/bitcoin/bitcoin/pull/7692/files?diff=split)
https://bitcoin.org/en/alert/2016-11-01-alert-retirement

the bitcoin test fails Gracefully now due to a separate issue:

src/test/main_tests.cpp(62): error: in "main_tests/subsidy_limit_test": check nSum == 12500000000000ULL has failed [1250000000 != 12500000000000]

this is to do with the difference in slow start from zcash to zclassic -- it is an artifact not changed to match zclassic:

// Mining slow start
for (int nHeight = 0; nHeight < consensusParams.nSubsidySlowStartInterval; nHeight ++) {
CAmount nSubsidy = GetBlockSubsidy(nHeight, consensusParams);
BOOST_CHECK(nSubsidy <= 12.5 * COIN);
nSum += nSubsidy;
BOOST_CHECK(MoneyRange(nSum));
}
BOOST_CHECK_EQUAL(nSum, 12500000000000ULL);

@heyrhett set slow start to 2 blocks:

https://github.com/z-classic/zclassic/blob/master/src/chainparams.cpp#L41

consensus.nSubsidySlowStartInterval = 2 (zcash= 20000)

we need to change the test to match the zclassic values. 3 tests in total line 51 to line 85 in main_tests.cpp

opening a new issue regarding this, as it is something else unrelated to previous.