Fix re-migration of existing CA bundles

[cipherboy]

Later in Vault 1.11, 1.12, and 1.13's release, we added a fix for a regression regarding chain building that resulted in a small migration to rebuild all issuer's chains within the mount. This resulted in a second storage migration "version" being created, which was unfortunate as the existing logic resulted in the entire migration being re-attempted:

    if (migrationInfo.migrationLog == nil) ||
        (migrationInfo.migrationLog.Hash != migrationInfo.legacyBundleHash) ||
        (migrationInfo.migrationLog.MigrationVersion != latestMigrationVersion) {  /// <<--- HERE

As a result, if the migrated legacy issuers (from storage version 0/1) were deleted prior to version 2's upgrade (to 1.13.0, 1.12.2, and 1.11.6), these would be recreated and would need to be removed again. Additionally, when managed keys were in use (in Vault Enterprise), an error like:

Error during migration of PKI mount: failed to lookup public key from managed key: no managed key found with uuid

would be visible in the logs. This only affects issuers created prior to upgrading to Vault 1.11.

Related: VAULT-17307

[schavis]

Made some editorial suggestions to improve content accessibility. Let me know if you have any questions :)

[schavis]

Suggested change

This has been fixed in Vault 1.14.0, 1.13.4, 1.12.8, and 1.11.12.

Suggest deleting this line and making the information easier to find by highlighting it at the beginning.

[cipherboy]

@schavis Mind re-reviewing with the updates? Thanks!

[schavis]

Minor tweaks for active voice