fix make scrambled password segmentation fault bug when password longer than 26 characters

[heat1024]

Comment Hello, I found a segmentation fault bug when use long long password(longer than 26 characters. like 32) in make_scrambled_password function.

During create password by sha1, temporary variable h0 will set zero for clear. But, for now, set zero to h0 until length of password .

h0 variable is just 20 bytes, but password can set 255 characters. So if password is too long, I thing it will cleanup data even outside of the h0 variable range.

In this PR, make set zero h0 just for size of h0 for not occur segmentation fault.