FIX temporary: prevent exception on free blocks

src/components/DNSRecordTypeCard.vue

@@ -81,7 +81,7 @@
             <template
                 v-for="(item, item_index) in fs_sliced_records">
               <template
-                  v-if="record_type === 'A' && sort_by === 'data'  && !filter && item.data in upperIfAsc() && ((item_index-1 < 0 && fs_sliced_records.length !== 1) || fs_sliced_records[item_index-1].data !== item.data)">
+                  v-if="record_type === 'A' && sort_by === 'data'  && !filter && item.data in upperIfAsc() && ((item_index-1 < 0 && fs_sliced_records.length !== 1) || fs_sliced_records[item_index-1]?.data !== item.data)">
                 <BCDFreeAddressBlock :key="'block_upper_' + item.data + '_' + block_index"
                                      v-for="(block,block_index) in reverseIfDesc(upperIfAsc()[item.data].containing_blocks)"
                                      :create_item_func="createRecord" :block="block"