Fix: Nil value for db.name attribute

[robertlaurin]

One of our users reported some log spam during migrations on their application.

It looks like we're expecting a db.name to be present when there might not be one available.

E, [2021-05-05T15:02:17.437321 #55630] ERROR -- : OpenTelemetry error: invalid span attribute value type NilClass for key 'db.name' on span 'set names'
E, [2021-05-05T15:02:17.440246 #55630] ERROR -- : OpenTelemetry error: invalid span attribute value type NilClass for key 'db.name' on span 'create database'

[ericmustin]

could be good to add a test to prevent a regression but generally lgtm

[robertlaurin]

@ericmustin

could be good to add a test to prevent a regression but generally lgtm

Hey yeah, sorry responding post merge. I agree, I find testing for the absence of a log kind of awkward and flakey as a form of test. It's possible I'm not seeing a more obvious reliable way of testing this change.

If you have any ideas here I can definitely add the test in a follow up PR.