Rescue DB connection error.

[DanielePalombo]

Summary

If the DB connection fails, the initializer shouldn't raise any error.

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[kennyadsl]

@DanielePalombo why should fail when the DB adapter is not present?

[DanielePalombo]

@kennyadsl My fault.

This PR aims to do exactly the opposite! The initializer should not fail if the DB connection fails.

I'm updating the PR and commit description