Inserted required property in the rename list field, to prevent the list from being unnamed

src/components/board/Stack.vue

@@ -35,7 +35,10 @@
 					{{ stack.title }}
 				</h3>
 				<form v-else @submit.prevent="finishedEdit(stack)">
-					<input v-model="copiedStack.title" v-focus type="text">
+					<input v-model="copiedStack.title"
+						v-focus
+						type="text"
+						required="required">
 					<input v-tooltip="t('deck', 'Add a new list')"
 						class="icon-confirm"
 						type="submit"