Add es.lua locale and removed unsused phrase

[Cocodrulo]

Describe Pull request
This PR brings the Spanish locale to the radio script. Also removes the unused locale on_radio which I couldn't find any use of it.

If your PR is to fix an issue mention that issue here

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? [no] (Put they are just locale it shouldn't be any problem at all)
• Does your code fit the style guidelines? [yes]
• Does your PR fit the contribution guidelines? [yes]