hs: HSDir do not accept v3 descriptors properly
When a v3 descriptor is uploaded, it goes through a series of validation including
encrypted_data_length_is_valid() which checks for the encrypted data size to be a multiple of
#define HS_DESC_PLAINTEXT_PADDING_MULTIPLE 128 but it's not true anymore becase we pad up to a minimum of 10000 bytes.
This is currently fixed upstream but wasn't backported to 030. It has been introduced in tor-0.3.0.1-alpha with commit cff1fd63f16.