security/vault: Update to 0.11.1.

SECURITY:

- Random Byte Reading in Barrier: Prior to this release, Vault was not
  properly checking the error code when reading random bytes for the IV for
  AES operations in its cryptographic barrier. Specifically, this means that
  such an IV could potentially be zero multiple times, causing nonce re-use
  and weakening the security of the key. On most platforms this should never
  happen because reading from kernel random sources is non-blocking and always
  successful, but there may be platform-specific behavior that has not been
  accounted for. (Vault has tests to check exactly this, and the tests have
  never seen nonce re-use.)

FEATURES:

- AliCloud Agent Support: Vault Agent can now authenticate against the
  AliCloud auth method.
- UI: Enable AliCloud auth method and Azure secrets engine via the UI.

IMPROVEMENTS:

- core: Logging level for most logs (not including secrets/auth plugins) can
  now be changed on-the-fly via `SIGHUP`, reading the desired value from
  Vault's config file

BUG FIXES:

- core: Ensure we use a background context when stepping down
- core: Properly check error return from random byte reading
- core: Re-add `sys/` top-route injection for now
- core: Properly store the replication checkpoint file if it's larger than the
  storage engine's per-item limit
- identity: Update MemDB with identity group alias while loading groups
- secrets/database: Fix nil pointer when revoking some leases
- secrets/pki: Fix sign-verbatim losing extra Subject attributes
- secrets/pki: Remove certificates from store when tidying revoked
  certificates and simplify API
- ui: JSON editor will not coerce input to an object, and will now show an
  error about Vault expecting an object
- ui: authentication form will now default to any methods that have been tuned
  to show up for unauthenticated users


(fhajny)