Constant bitcoin_qt::HTML_HACK_SP

pub const HTML_HACK_SP: &'static str = "<span style='white-space: nowrap; font-size: 6pt'> </span>";

| QMessageBox seems to have a bug whereby it | doesn’t display thin/hair spaces correctly. | Workaround is to display a space in a small | font. If you change this, please test that it | doesn’t cause the parent span to start | wrapping.