Fix uninitialized variables

src/globalshortcuts/globalshortcut.cpp

@@ -39,6 +39,7 @@ GlobalShortcut *GlobalShortcut::initialized_ = nullptr;
 QHash<QPair<quint32, quint32>, GlobalShortcut*> GlobalShortcut::internal_shortcuts_;
 
 GlobalShortcut::GlobalShortcut(QObject *parent) : QObject(parent),
+  backend_(nullptr),
   qt_key_(Qt::Key(0)),
   qt_mods_(Qt::NoModifier),
   native_key_(0),

src/globalshortcuts/globalshortcutgrabber.cpp

@@ -35,7 +35,8 @@
 #include "ui_globalshortcutgrabber.h"
 
 GlobalShortcutGrabber::GlobalShortcutGrabber(QWidget *parent)
-    : QDialog(parent), ui_(new Ui::GlobalShortcutGrabber) {
+    : QDialog(parent), ui_(new Ui::GlobalShortcutGrabber), wrapper_(nullptr) {
+
   ui_->setupUi(this);
 
   modifier_keys_ << Qt::Key_Shift << Qt::Key_Control << Qt::Key_Meta << Qt::Key_Alt << Qt::Key_AltGr;