fix(NcAppContent): avoid double content mount

Signed-off-by: Grigorii K. Shartsev <me@shgk.me>

Author: ShGKme

src/components/NcAppContent/NcAppContent.vue

@@ -92,12 +92,12 @@ export default {
 </docs>
 
 <template>
-	<main id="app-content-vue" class="app-content no-snapper" :class="{ 'app-content--has-list': hasList }">
+	<main id="app-content-vue" class="app-content no-snapper" :class="{ 'app-content--has-list': !!$scopedSlots.list }">
 		<h1 v-if="pageHeading" class="hidden-visually">
 			{{ pageHeading }}
 		</h1>
 
-		<template v-if="hasList">
+		<template v-if="!!$scopedSlots.list">
 			<!-- Mobile view does not allow resizeable panes -->
 			<div
 				v-if="isMobile || layout === 'no-split'"
@@ -145,7 +145,7 @@ export default {
 			</div>
 		</template>
 		<!-- @slot Provide the main content to the app content -->
-		<slot v-if="!hasList" />
+		<slot v-if="!$scopedSlots.list" />
 	</main>
 </template>
 
@@ -309,8 +309,6 @@ export default {
 	data() {
 		return {
 			contentHeight: 0,
-			hasList: false,
-			hasContent: false,
 			swiping: {},
 			listPaneSize: this.restorePaneConfig(),
 		}
@@ -406,18 +404,13 @@ export default {
 		},
 	},
 
-	updated() {
-		this.checkSlots()
-	},
-
 	mounted() {
 		if (this.allowSwipeNavigation && !this.disableSwipe) {
 			this.swiping = useSwipe(this.$el, {
 				onSwipeEnd: this.handleSwipe,
 			})
 		}
 
-		this.checkSlots()
 		this.restorePaneConfig()
 	},
 
@@ -461,12 +454,6 @@ export default {
 			logger.debug('AppContent pane config', { size: listPaneSize })
 		},
 
-		// $slots is not reactive, we need to update this manually
-		checkSlots() {
-			this.hasList = !!this.$scopedSlots.list
-			this.hasContent = !!this.$scopedSlots.default
-		},
-
 		// browserStorage is not reactive, we need to update this manually
 		restorePaneConfig() {
 			const listPaneSize = parseInt(browserStorage.getItem(this.paneConfigID), 10)