fix(CreateCommunityPopup): reset discord filelist when modal is opened

Prior to this commit we would reset the file list (and categories and
channels) whenever the `CreateCommunityPopup` was closed.

This made sense because at that point we could assume that the user has
decided to somehow stop the process of an import, so the next time the
modal is opened again, we want that data to be reset.

However, it turned out that this introduced a bug in the scenario where
and import is running, and while it's running, when the user decides to
hide the progress modal, it would reset the warnings count, resulting in
the progress banner to show an invalid state until the next progress
signal was emitted.

We don't want to reset this data every time we close the modal. We only
want to reset it when we know there's no import in progress.

Fixes #7787

ui/app/AppLayouts/CommunitiesPortal/popups/CreateCommunityPopup.qml

@@ -74,19 +74,16 @@ StatusStackModal {
     onAboutToShow: {
         nameInput.input.edit.forceActiveFocus()
         if (root.isDiscordImport) {
+            if (!root.store.discordImportInProgress) {
+                root.store.clearFileList()
+                root.store.clearDiscordCategoriesAndChannels()
+            }
             for (let i = 0; i < discordPages.length; i++) {
                 stackItems.push(discordPages[i])
             }
         }
     }
 
-    onClosed: {
-        if (root.isDiscordImport) {
-            root.store.clearFileList()
-            root.store.clearDiscordCategoriesAndChannels()
-        }
-    }
-
     readonly property list<Item> discordPages: [
         ColumnLayout {
             id: fileListView