Fix crash on exit when -createwalletbackups=0 (#1810)

Author: codablock

src/qt/overviewpage.cpp

@@ -132,7 +132,8 @@ OverviewPage::OverviewPage(const PlatformStyle *platformStyle, QWidget *parent)
     currentWatchOnlyBalance(-1),
     currentWatchUnconfBalance(-1),
     currentWatchImmatureBalance(-1),
-    txdelegate(new TxViewDelegate(platformStyle, this))
+    txdelegate(new TxViewDelegate(platformStyle, this)),
+    timer(nullptr)
 {
     ui->setupUi(this);
     QString theme = GUIUtil::getThemeName();
@@ -195,7 +196,7 @@ void OverviewPage::handleOutOfSyncWarningClicks()
 
 OverviewPage::~OverviewPage()
 {
-    if(!fLiteMode && !fMasterNode) disconnect(timer, SIGNAL(timeout()), this, SLOT(privateSendStatus()));
+    if(timer) disconnect(timer, SIGNAL(timeout()), this, SLOT(privateSendStatus()));
     delete ui;
 }