wxQt: Fix a memory leak when setting maxlen for a multiline textctrl

src/qt/textctrl.cpp

@@ -126,6 +126,7 @@ class wxQtTextEdit : public wxQtEventSignalHandler< QTextEdit, wxTextCtrl >
 {
 public:
     wxQtTextEdit( wxWindow *parent, wxTextCtrl *handler );
+    ~wxQtTextEdit();
 
     virtual wxString GetValueForProcessEnter() override
     {
@@ -778,6 +779,11 @@ wxQtTextEdit::wxQtTextEdit( wxWindow *parent, wxTextCtrl *handler )
             });
 }
 
+wxQtTextEdit::~wxQtTextEdit()
+{
+    delete m_textLimiter;
+}
+
 void wxQtTextEdit::SetMaxLength(unsigned long len)
 {
     const unsigned long maxlen = std::numeric_limits<int>::max();