Incorrect English/Spanish translation in "Add link" editor of "External link editor"

Pre-conditions:

1. User is registered and logged.
2. User has Admin permission for Jcommune.
3. Administration mode is enabled

Steps to reproduce:

1. Select the English/Spanish language in the top right
2. Open "External link editor"
3. Click on "Add" button - "Add link" editor is opened
4. For English: view the text field for URL input
5. For Spanish: view the text field for URL and text field for hint input

Translation for English language:
Actual result: "URL link"
Expected result: "Specify a link"

Translation for Spanish language:

• Field for URL input:
  Actual result: "URL del enlace"
  Expected result: "Especifique enlace"

• Field for the hint input:
  Actual result: "Ayuda"
  Expected result: "Indirecta"

Issue exists also in "Edit link" editor of "External link editor".