Sort alphabetically the recovered feeds

Having feed sorted by names rather than by folder ID would be more user
friendly.
Follow-up of PR ViennaRSS#1754, working on issue ViennaRSS#1768

Vienna/Sources/Main window/FoldersTree.m

@@ -157,7 +157,8 @@ -(void)reloadDatabase:(NSArray *)stateArray
     [self.rootNode removeChildren];
     if (![self loadTree:[[Database sharedManager] arrayOfFolders:VNAFolderTypeRoot] rootNode:self.rootNode]) {
         // recover from problems by putting missing folders under root node
-        NSArray *allFolders = [[Database sharedManager] arrayOfAllFolders];  // all RSS and group folders
+        NSArray *allFolders = [[[Database sharedManager] arrayOfAllFolders]
+                               sortedArrayUsingSelector:@selector(folderNameCompare:)]; // all RSS and group folders
         NSArray *installedFolders = [self folders:0];  // RSS folders already present
         for (Folder *folder in allFolders) {
             if ((folder.type == VNAFolderTypeRSS || folder.type == VNAFolderTypeOpenReader)