Fix hang in nodejs etl on mysql connection failure.

[jpwhite4]

Description

By code inspection there is a possible hang condition if
the mysql connection fails in the ETL logging part of the
code.

Tests performed

I tested this code change manually by editing the etl_profile and
temporarily editing the mysql configuration so that the connection
would fail:

mysqlConfig.host = 'qweqw';

The output of the process was then:

2021-01-05T21:13:39.077Z - error: {"code":"ENOTFOUND","errno":"ENOTFOUND","syscall":"getaddrinfo","hostname":"qweqw","host":"qweqw","port":"3306","fatal":true}
2021-01-05T21:13:39.077Z - error: {"code":"ENOTFOUND","errno":"ENOTFOUND","syscall":"getaddrinfo","hostname":"qweqw","host":"qweqw","port":"3306","fatal":true}
2021-01-05T21:13:39.083Z - error: {"code":"ENOTFOUND","errno":"ENOTFOUND","syscall":"getaddrinfo","hostname":"qweqw","host":"qweqw","port":"3306","fatal":true}
2021-01-05T21:13:39.161Z - error: {"code":"ENOTFOUND","errno":"ENOTFOUND","syscall":"getaddrinfo","hostname":"qweqw","host":"qweqw","port":"3306","fatal":true}
2021-01-05T21:13:39.172Z - error: {"code":"ENOTFOUND","errno":"ENOTFOUND","syscall":"getaddrinfo","hostname":"qweqw","host":"qweqw","port":"3306","fatal":true}

and then the process exited. Without the bug fix the output looks like this:

2021-01-05T21:15:14.519Z - error: undefined
2021-01-05T21:15:14.547Z - error: undefined
2021-01-05T21:15:14.555Z - error: undefined
2021-01-05T21:15:14.608Z - error: undefined
2021-01-05T21:15:14.615Z - error: undefined

and the process hangs forever.