sjcl: use floor division in truncate_iv() for python3 compat
sjcl: use floor division in truncate_iv() for python3 compat

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ERROR: test_decrypt (__main__.Test)
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Traceback (most recent call last):
  File "tests/simple.py", line 35, in test_decrypt
    SJCL().decrypt(cyphertext, "shared_secret"),
  File "/home/awelzel/evidation/dataeng/loop/health_label_vault/external/sjcl/sjcl/sjcl.py", line 129, in decrypt
    nonce = truncate_iv(iv, len(ciphertext)*8, data["ts"])
  File "/home/awelzel/evidation/dataeng/loop/health_label_vault/external/sjcl/sjcl/sjcl.py", line 61, in truncate_iv
    while (L < 4) and ((ol >> (8*L))) > 0:
TypeError: unsupported operand type(s) for >>: 'float' and 'int'

berlincode/sjcl