Improve error message when URL is empty string

[MarioRodrigues10]

• Because this PR includes a bug fix, relevant tests have been included.
• Because this PR includes a new feature, the change was previously discussed on an Issue or with someone from the team.
• I didn't do anything of this.

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This PR was created in order to solve #2730

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[fvictorio]

Hi @MarioRodrigues10, I doubt this PR does what you think it does. The issue is about showing a better error in certain scenarios, and related to how we validate the config. This is changing the value used in a comparison (and it probably introduces a bug).