get_merkle_root fails when at any level of the tree, except the deepest one, an odd number occurs

[vanschelven]

i.e. it fails on 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 17 etc. number of transactions

[aizuon]

I have ported this to C++ with a deeper implementation. The following commit fixes this issue in my project: aizuon/tiny-coin@50f3fed