fix: show proper validation error message when user inputs old path in redirect section

[victorchrollo14]

Description

fixes: #5050

fixes the validation error message when user enters old path in redirects section.

Steps for reproduction

1. go to project settings.
2. redirects tab
3. enter a url like https://website.org in old path input field.
4. the validation error will we shown in the tooltip.

Code Review

• hi @kof, I need you to do
  • conceptual review (architecture, feature-correctness)
  • detailed review (read every line)
  • test it on preview

Before requesting a review

• made a self-review
• added inline comments where things may be not obvious (the "why", not "what")

Before merging

• tested locally and on preview environment (preview dev login: 0000)
• updated test cases document
• added tests
• if any new env variables are added, added them to .env file

[kof]

lgtm

[TrySound]

Thanks!