duplicated reminder no error message to handle

[nus-pe-bot]

Attempted to add a duplicated reminder but there was no error message to handle it.

The duplicate error message can be seen on the terminal on the left.

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_{[original: nus-cs2103-AY1920S1/pe-interim#965]}

[kerwin97]

Team's Response

There should have been an error message on the screen as i have put in the necessary code to check for that as seen in the terminal. will fix it thank you!

Duplicate status (if any):

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