The description of the Alfred API key does not match the wiki document

[yillkid]

According the description of wiki. API token for Alfred of MAM send/receive should be optional, but it's not in actual test.

Reproduce:

Without x-api-key

Request:

curl http://node.deviceproof.org:6699/mam/send \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{"data": {"seed": "IUFXQETKSHDYPFUDO9ILVCAVQIXOHXKCECZYFLPBNVIX9JUXQZJE9URQEEUWPWYZOIACTCGZX9IDIODCA","message": "this is testing message -1 "},"protocol": "MAM_V1"}'

Response:

{"message": "Internal service error"}

With x-api-key

Request:

curl http://node.deviceproof.org:6699/mam/send \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{"x-api-key": "3bff60110c9f0e40628031b16dfefe2eb45a6b0c2237b49ef5109f9aa8eb19a8", "data": {"seed": "IUFXQETKSHDYPFUDO9ILVCAVQIXOHXKCECZYFLPBNVIX9JUXQZJE9URQEEUWPWYZOIACTCGZX9IDIODCA","message": "this is testing message -1 "},"protocol": "MAM_V1"}'

Response:

{"bundle_hash":"ANUZHQGYLNGZUIJKLOPGJCNBBVLSGOLLKDUTPXJKBIRIUKPLQXHH9YANGCYGNLTCLJAVRYLHFZDIPSQJW","chid":"CERTKXUBKWXPTUNCU9MIEJNWOSSKBPWQYSZ9DGGFYSBOCENNXIEFVLRJTU9FMKYFJQR9JVEQPVZQYADPS","msg_id":"T9OZCUWKRSJCHQAZPEZPF"}

[splasky]

Related #694.

[howjmay]

it has been handled in #694