Revert "Media search dialog: Only try to abort request if possible"

Per bug 59604. The TypeError isn't coming from calling ".abort". That
method is always there and part of every jqXHR object, always.

This reverts commit c5dbc13c65f388f362d453f51011e33b008eadc5.

Change-Id: I43bb53d8c98ca83688020c029d9a3db2c34d54ee
Merge "Revert "Media search dialog: Only try to abort request if possible""