Wrong error message in the plugin configs

[AayushChaudhary0001]

This issue has been found while testing that the user receives an irrelevant error on saving the invalid dates.

Steps to reproduce:

• Manually enter the date which is invalid and click on create legal hold.
  (for example: 31/06/2024)

The user receives a message to fill out the mandatory field even if it is already filled. In fact, the error presented should indicate that the data entered is invalid.

[AayushChaudhary0001]

This issue is getting fixed in #113