Revert "Clear classifier data when folder deleted"

This reverts commit ae0d96fbd8.

app/src/main/java/eu/faircode/email/MessageClassifier.java

@@ -177,20 +177,19 @@ public class MessageClassifier {
 
     private static String classify(EntityMessage message, @NonNull String currentClass, @NonNull List<String> texts, boolean added, @NonNull Context context) {
         State state = new State();
-        DB db = DB.getInstance(context);
 
         // Check classes
-        boolean clear = false;
+        DB db = DB.getInstance(context);
         for (String clazz : new ArrayList<>(classMessages.get(message.account).keySet())) {
             EntityFolder folder = db.folder().getFolderByName(message.account, clazz);
             if (folder == null) {
                 EntityLog.log(context, EntityLog.Type.Classification, message,
-                        "Classifier deleted folder=" + message.account + ":" + clazz);
-                clear = true;
+                        "Classifier deleting folder class=" + message.account + ":" + clazz);
+                classMessages.get(message.account).remove(clazz);
+                for (String word : wordClassFrequency.get(message.account).keySet())
+                    wordClassFrequency.get(message.account).get(word).remove(clazz);
             }
         }
-        if (clear)
-            clear(context);
 
         Log.i("Classifier texts=" + texts.size());
         for (String text : texts) {