account auths doesn't work in multisig accounts

[only-dev-time]

If authorities in the multisig account only contains account authorities, the signatures will not be accepted:

key authorities works

[only-dev-time]

Account auth works if the weight of all signatures corresponds to the threshold.
example:

threshold = 40
acc1 (owner) = 20
acc2 = 10
acc3 = 10
acc4 = 10

if all accounts sign --> error: irrelevant signature
if acc1, acc2, acc4 (weight = 40) sign --> no error