AT:

• Optimize startup aborts if the elasticsearch schema doesn't comply to the Optimize version started (due to no upgrade run, upgrade failed, starting an older Optimize version etc.)
• Optimize startup aborts before any elasticsearch schema initialization/mapping updating is done (the schemaManager tries to initialize missing indexes or updates existing ones, this should only happen if there is no version in metadata yet or if it matches the current version)

Context:
The metadataVersion check is currently done after the SchemaManager has already run, this could lead to inconsistent index setup if Optimize is started before an upgrade or an older version of Optimize after an upgrade etc.