Import/export classifier data

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

@@ -628,6 +628,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                 jexport.put("accounts", jaccounts);
                 jexport.put("answers", janswers);
                 jexport.put("certificates", jcertificates);
+                jexport.put("classifier", MessageClassifier.toJson());
                 jexport.put("settings", jsettings);
 
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
@@ -952,6 +953,9 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                         }
                     }
 
+                    if (jimport.has("classifier"))
+                        MessageClassifier.fromJson(jimport.getJSONObject("classifier"));
+
                     // Settings
                     SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
                     SharedPreferences.Editor editor = prefs.edit();