removed unused asset

examples/files/external.svg

-<?xml version="1.0" ?><svg height="48" viewBox="0 0 48 48" width="48" xmlns="http://www.w3.org/2000/svg"><path d="M0 0h48v48h-48z" fill="none"/><path fill="#ffffff" d="M38 38h-28v-28h14v-4h-14c-2.21 0-4 1.79-4 4v28c0 2.21 1.79 4 4 4h28c2.21 0 4-1.79 4-4v-14h-4v14zm-10-32v4h7.17l-19.66 19.66 2.83 2.83 19.66-19.66v7.17h4v-14h-14z"/></svg>
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