Merge bitcoin-core#826: OptionsDialog: Allow Maximize of window

3dbd94b GUI/OptionsDialog: Allow Maximize of window (Luke Dashjr)

Pull request description:

ACKs for top commit:
  hebasto:
    ACK 3dbd94b.

Tree-SHA512: 24a94840d97510ce5760c3099a765fb2f5d107d99a8f72757f509eefdaf35cb2d4d7f3243866bf6dc635fe83bb73b422e3cae2bd161d9b4b6f2e3d77bfd27353

src/qt/optionsdialog.cpp

@@ -87,7 +87,7 @@ void setupFontOptions(QComboBox* cb, QLabel* preview)
 }
 
 OptionsDialog::OptionsDialog(QWidget* parent, bool enableWallet)
-    : QDialog(parent, GUIUtil::dialog_flags),
+    : QDialog(parent, GUIUtil::dialog_flags | Qt::WindowMaximizeButtonHint),
       ui(new Ui::OptionsDialog)
 {
     ui->setupUi(this);