Reduce size of download button on macOs

This should fix readability issues on macOs. On at least some version of macOS, the font color switched to white when the button's height was increased

src/browser.cpp

@@ -20,6 +20,11 @@ Browser::Browser(QWidget *parent) :
 {
     ui->setupUi(this);
 
+#if defined(Q_OS_MACOS)
+    // Remove minimum size of download button on macOS as it also changes the default font color
+    ui->syncPushButton->setMinimumHeight(0);
+#endif
+
     // Hinzufügen der Daten zur Baumansicht
     l2pItemModel = new L2pItemModel();
     proxy = l2pItemModel->getProxy();