Minor: changed tab character into space in license header

src/qml/MainWindow.qml

src/qml/about/AboutPage.qml

src/qml/about/AuthorsPage.qml

src/qml/about/ChangesPage.qml

src/qml/about/DonorsPage.qml

src/qml/about/HelpPage.qml

src/qml/about/LicensePage.qml

src/qml/about/QtPage.qml

src/qml/about/SupportPage.qml

src/qml/about/TaboutNootka.qml

src/qml/about/TextBackground.qml

src/qml/score/Clef.qml

src/qml/score/KeySignature.qml

src/qml/score/Meter.qml

src/qml/score/NoteSegment.qml

src/qml/score/Score.qml

src/qml/score/Staff.qml

src/qml/settings/ColorButton.qml

src/qml/settings/GlobalPage.qml

src/qml/settings/ScorePage.qml