fix: avoid crash when deleting account

GitLab: #1173
Change-Id: Id30f259ce286ea8fb76af5aee59ed49edb99011a

src/app/currentaccounttomigrate.cpp

@@ -125,6 +125,8 @@ CurrentAccountToMigrate::slotAccountStatusChanged(const QString& accountId)
 void
 CurrentAccountToMigrate::slotAccountRemoved(const QString& accountId)
 {
+    if (accountToMigrateList_.isEmpty() || accountToMigrateList_.indexOf(accountId) < 0)
+        return;
     if (accountToMigrateList_.removeOne(accountId))
         updateData();
     if (accountToMigrateList_.isEmpty())