Describe the bug

User parsing #8048 the redis URI will always set config.user even in the case of '' empty string.

To reproduce

Given the redis URI following the standard format:

redis://:<password>@<host>:<port>

The user will be parsed as '' empty string. Failing to AUTH as the default user.

Expected behavior

The same behavior as the redis URI:

redis://<password>@<host>:<port>

Which will correctly AUTH as the default user.