fix(files): do not even try to fetch a preview if èhas-preview` is false

Signed-off-by: John Molakvoæ (skjnldsv) <skjnldsv@protonmail.com>

Author: skjnldsv

apps/files/src/components/FileEntry/FileEntryPreview.vue

@@ -16,6 +16,7 @@
 
 		<!-- Decorative image, should not be aria documented -->
 		<img v-else-if="previewUrl && backgroundFailed !== true"
+			:key="source.fileid"
 			ref="previewImg"
 			alt=""
 			class="files-list__row-icon-preview"
@@ -134,6 +135,17 @@ export default Vue.extend({
 				return null
 			}
 
+			if (this.source.attributes['has-preview'] !== true
+				&& this.source.mime !== undefined
+				&& this.source.mime !== 'application/octet-stream'
+			) {
+				const previewUrl = generateUrl('/core/mimeicon?mime={mime}', {
+					mime: this.source.mime,
+				})
+				const url = new URL(window.location.origin + previewUrl)
+				return url.href
+			}
+
 			try {
 				const previewUrl = this.source.attributes.previewUrl
 					|| generateUrl('/core/preview?fileId={fileid}', {