increase timeout for bip39 tests
increase timeout for bip39 tests

Every once in a while, the BIP39 tests fail on my computer for taking
too long in a browser. BIP39 is deliberately slow due to its use of
PBKDF2. By increasing the default timeout from 2000 to 4000 ms, this
problem should be all but eliminated on new computers.

ryanxcharles/fullnode,martindale/fullnode,ryanxcharles/fullnode,martindale/fullnode