ephemeral_public_keys table grows indefinitely about sydent

[DMRobertson]

Stats for vector.im db. Assuming this number is in bytes (sqlite docs just say "Total storage space"), the largest table is 750MB). ephemeral_public_keys is the sixth largest stored thing.

sqlite> SELECT sum(pgsize), name FROM dbstat GROUP BY name ORDER BY sum(pgsize) desc;
sum(pgsize)|name
769774592|invite_tokens
709062656|tokens
608440320|sqlite_autoindex_tokens_1
514449408|invite_token_token
184473600|ephemeral_public_keys_index
181351424|ephemeral_public_keys
118963200|invite_token_medium_address
108321792|global_threepid_associations
31805440|accounts
28598272|sqlite_autoindex_accounts_1
24621056|local_threepid_associations
16984064|accepted_terms_urls_idx
14488576|accepted_terms_urls
10859520|global_threepid_lookup_hash
9791488|global_threepid_medium_address
9785344|local_threepid_medium_address
9160704|global_threepid_medium_lower_address
5345280|global_threepid_originServer_originId
71680|threepid_validation_sessions
20480|threepid_token_auths
12288|threepid_validation_sessions_mtime
8192|sqlite_master
1024|hashing_metadata
1024|name
1024|peer_pubkeys
1024|peername_alg
1024|peers
1024|sqlite_sequence