[qt] coincontrol: Remove unused qt4 workaround

Author: MarcoFalke

src/qt/coincontroldialog.cpp

@@ -118,10 +118,6 @@ CoinControlDialog::CoinControlDialog(const PlatformStyle *_platformStyle, QWidge
     // (un)select all
     connect(ui->pushButtonSelectAll, SIGNAL(clicked()), this, SLOT(buttonSelectAllClicked()));
 
-    // change coin control first column label due Qt4 bug.
-    // see https://github.com/bitcoin/bitcoin/issues/5716
-    ui->treeWidget->headerItem()->setText(COLUMN_CHECKBOX, QString());
-
     ui->treeWidget->setColumnWidth(COLUMN_CHECKBOX, 84);
     ui->treeWidget->setColumnWidth(COLUMN_AMOUNT, 110);
     ui->treeWidget->setColumnWidth(COLUMN_LABEL, 190);