Fix _xfconf_gvalue_from_string for floating point numbers.
After transitioning xfce4-terminal to xfconf I found out that xfconf is unable to read double properties. Here is a fix (based on Thunar's preferences code).
After transitioning xfce4-terminal to xfconf I found out that xfconf is unable to read double properties. Here is a fix (based on Thunar's preferences code).