Finding tasks with complete status returns incomplete tasks

[nus-pe-bot]

Description of the bug:

Using the command findT s/complete returns the incomplete tasks, instead of the complete tasks.

To reproduce:

Steps:

1. Add 2 different tasks using addT.
2. markT one of the 2 tasks.
3. Run the command findT s/complete.
4. The incomplete tasks are returned.

Expected behaviour:

The expected behaviour is that the complete tasks would be shown.

Screenshots/Video:
video:https://raw.githubusercontent.com/nus-cs2103-AY2223S1/pe/master/files/d480c93a-f8c5-4882-baf5-c7b90a7ece24.mp4

Justification:

This is a feature that a user will likely use very commonly to differentiate between completed and incomplete tasks. It is also not difficult for a user to happen upon this bug.

---

_{[original: nus-cs2103-AY2223S1/pe-interim#3444] [original labels: severity.Medium type.FunctionalityBug]}

[junwei-tan]

Team's Response

This is a duplicate of #496.

Duplicate status (if any):

Duplicate of #496