Make it compile against last qt5.15

src/filter/filteractions/filteractionaddtoaddressbook.cpp

@@ -249,7 +249,11 @@ QString FilterActionAddToAddressBook::argsAsString() const
 
 void FilterActionAddToAddressBook::argsFromString(const QString &argsStr)
 {
+#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
     const QStringList parts = argsStr.split(QLatin1Char('\t'), QString::KeepEmptyParts);
+#else
+    const QStringList parts = argsStr.split(QLatin1Char('\t'), Qt::KeepEmptyParts);
+#endif
     const QString firstElement = parts[ 0 ];
     if (firstElement == QLatin1String("From")) {
         mHeaderType = FromHeader;

src/snippets/snippetattachmentwidget.cpp

@@ -71,7 +71,11 @@ void SnippetAttachmentWidget::clear()
 void SnippetAttachmentWidget::slotSelectAttachment()
 {
     QPointer<MailCommon::SnippetSelectAttachmentDialog> dlg = new MailCommon::SnippetSelectAttachmentDialog(this);
+#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
     dlg->setAttachments(mLineEdit->text().split(QLatin1Char(','), QString::SkipEmptyParts));
+#else
+    dlg->setAttachments(mLineEdit->text().split(QLatin1Char(','), Qt::SkipEmptyParts));
+#endif
     if (dlg->exec()) {
         mLineEdit->setText(dlg->attachments().join(QLatin1Char(',')));
         Q_EMIT wasChanged();