Allow moving onto self when multiple selecting

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

@@ -948,6 +948,9 @@ class Core {
         EntityFolder target = db.folder().getFolder(id);
         if (target == null)
             throw new FolderNotFoundException();
+        if (folder.id.equals(target.id))
+            return;
+
         IMAPFolder itarget = (IMAPFolder) istore.getFolder(target.name);
 
         // Get source messages
@@ -1105,6 +1108,8 @@ class Core {
         EntityFolder target = db.folder().getFolder(id);
         if (target == null)
             throw new FolderNotFoundException();
+        if (folder.id.equals(target.id))
+            return;
 
         // Move from trash/drafts only
         if (!EntityFolder.TRASH.equals(folder.type) &&

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

@@ -2698,6 +2698,9 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                         if (account.protocol == EntityAccount.TYPE_IMAP)
                             result.accounts.add(account);
 
+                if (result.folders.size() > 1)
+                    result.folders = new ArrayList<>();
+
                 return result;
             }