Fix app link icon reset handling

dashboard/src/components/ApplinkDialog.vue

@@ -74,7 +74,6 @@ function onIconChanged(file) {
 
 function onResetIcon() {
   iconFile.value = '';
-  imagePicker.value.clear(`${API_ORIGIN}/img/appicon_fallback.png`);
 }
 
 async function onSubmit() {
@@ -194,8 +193,7 @@ defineExpose({
 
         <div>
           <label for="previewIcon">{{ $t('app.display.icon') }}</label>
-          <ImagePicker ref="imagePicker" v-if="iconUrl" :src="iconUrl" :fallback-src="`${API_ORIGIN}/img/appicon_fallback.png`" @changed="onIconChanged" size="512" display-height="80px"/>
-          <span class="actionable" @click="onResetIcon()">{{ $t('app.applinks.clearIconAction') }}</span> - <span class="text-small">{{ $t('app.applinks.clearIconDescription') }}</span>
+          <ImagePicker ref="imagePicker" v-if="iconUrl" :src="iconUrl" :fallback-src="`${API_ORIGIN}/img/appicon_fallback.png`" :unset-handler="mode === 'new' ? null : onResetIcon" @changed="onIconChanged" size="512" display-height="80px" style="width: 80px"/>
         </div>
 
         <FormGroup>