Use uniform_int_distribution for generating PINs

app/gui/computermodel.cpp

@@ -2,6 +2,8 @@
 
 #include <QThreadPool>
 
+#include <random>
+
 ComputerModel::ComputerModel(QObject* object)
     : QAbstractListModel(object) {}
 
@@ -135,6 +137,16 @@ void ComputerModel::renameComputer(int computerIndex, QString name)
     m_ComputerManager->renameHost(m_Computers[computerIndex], name);
 }
 
+// TODO: Use QRandomGenerator when we drop Qt 5.9 support
+QString ComputerModel::generatePinString()
+{
+    std::uniform_int_distribution<int> dist(0, 9999);
+    std::random_device rd;
+    std::mt19937 engine(rd());
+
+    return QString::asprintf("%04u", dist(engine));
+}
+
 void ComputerModel::pairComputer(int computerIndex, QString pin)
 {
     Q_ASSERT(computerIndex < m_Computers.count());