Editor: Fix hihglighting current line in read only editors.
Editor: Fix hihglighting current line in read only editors.

Task-number: QTCREATORBUG-10104
Change-Id: I3c4adb62c1cae61e9eb409a58359a687852023a1
Reviewed-by: Daniel Teske <d8a411aec9a206efedb4d45b75fe8d13f1e2b628@theqtcompany.com>
Reviewed-by: Eike Ziller <c142da16c73a95a82d35191bcc55b22835617128@theqtcompany.com>

xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator