Hi, 
The error is likely occurring due to missing headers or incorrect specifications in the sections of the config file. Refer to the Configuration file parser documentation to understand the correct format that configuration files must adhere to.

Hope it helps

The error tells that the file:

/etc/odoo/odoo.conf

has wrong format.

It should have section headers. Example:

[DEFAULT]
ServerAliveInterval = 45
Compression = yes

And it should have UTF-8 encoding (without BOM).

I have found it by searching for "configparser.MissingSectionHeaderError: File contains no section headers" in google.