Select root permissions radio button when new partition dialog is first created.

src/gui/newdialog.cpp

@@ -140,6 +140,7 @@ void NewDialog::setupDialog()
     };
     connect(&dialogWidget().comboFileSystem(), QOverload<int>::of(&QComboBox::currentIndexChanged), this, showPermissionsGroup);
     showPermissionsGroup();
+    dialogWidget().radioRootPermissions().setChecked(true);
 }
 
 void NewDialog::setupConnections()

src/gui/sizedialogwidget.h

@@ -74,6 +74,11 @@ public:
         return *m_RadioLogical;
     }
 
+    QRadioButton& radioRootPermissions() {
+        Q_ASSERT(m_permissionOnlyRoot);
+        return *m_permissionOnlyRoot;
+    }
+
     QComboBox& comboFileSystem() {
         Q_ASSERT(m_ComboFileSystem);
         return *m_ComboFileSystem;