message: Fix switching height to be more flexible
diff: @@ -407,8 +407,9 @@ class QtumEVMConstantinopleOpcodesTest(BitcoinTestFramework):
  self.reset()
  self.extcodehash_test(should_fail=True)
  - print('BEFORE RESTART', self.node.getblockcount())
  - self.restart_node(0, ['-constantinopleheight=2609', '-logevents'])
  + switch_height = self.node.getblockcount()
  + print('BEFORE RESTART', switch_height)
  + self.restart_node(0, ['-constantinopleheight={}'.format(switch_height), '-logevents'])
  self.reset()
  self.revert_test(should_fail=False)
  