[Qt] Initialize isLoading to false for CS view

Loading of the cold staking delegations list checks to see if `isLoading`
is true, and exit's out if it is. this check is used to prevent double
loading, but on some systems `isLoading` is initialized as `true`, so
the loading of CS delegations will never occur.

This changes to initialization to be explicitly `false`.

Github-Pull: #1253
Rebased-From: d837803

src/qt/pivx/coldstakingwidget.cpp

@@ -69,7 +69,8 @@ class CSDelegationHolder : public FurListRow<QWidget*>
 
 ColdStakingWidget::ColdStakingWidget(PIVXGUI* parent) :
     PWidget(parent),
-    ui(new Ui::ColdStakingWidget)
+    ui(new Ui::ColdStakingWidget),
+    isLoading(false)
 {
     ui->setupUi(this);
     this->setStyleSheet(parent->styleSheet());