Remove code for pre Qt 5.15.0 versions

src/Application.cpp

@@ -294,11 +294,7 @@ bool Application::processTabsFromFileArgs(MainWindow *window)
         }
 
         QHash<QString, QString> lineTokens;
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
         QStringList lineParts = lineString.split(QStringLiteral(";;"), Qt::SkipEmptyParts);
-#else
-        QStringList lineParts = lineString.split(QStringLiteral(";;"), QString::SkipEmptyParts);
-#endif
 
         for (int i = 0; i < lineParts.size(); ++i) {
             QString key = lineParts.at(i).section(QLatin1Char(':'), 0, 0).trimmed().toLower();

src/ProcessInfo.cpp

@@ -380,11 +380,7 @@ private:
                 }
             } while (!statusLine.isNull() && uidLine.isNull());
 
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
             uidStrings << uidLine.split(QLatin1Char('\t'), Qt::SkipEmptyParts);
-#else
-            uidStrings << uidLine.split(QLatin1Char('\t'), QString::SkipEmptyParts);
-#endif
             // Must be 5 entries: 'Uid: %d %d %d %d' and
             // uid string must be less than 5 chars (uint)
             if (uidStrings.size() == 5) {

src/widgets/EditProfileDialog.cpp

@@ -1544,11 +1544,7 @@ void EditProfileDialog::setupButtonGroup(const ButtonGroupOptions &options, cons
         activeButton = options.buttons[0].button;
     }
     activeButton->setChecked(true);
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
     connect(options.group, QOverload<int>::of(&QButtonGroup::idClicked),
-#else
-    connect(options.group, QOverload<int>::of(&QButtonGroup::buttonClicked),
-#endif
             this, [this, options](int value) {
         if (options.preview) {
             preview(options.profileProperty, value);