#15 Encoding field not needed in gstm.desktop file

[Ryan Niebur]

N: The Encoding key is now deprecated by the FreeDesktop standard and all
N: strings are required to be encoded in UTF-8. This desktop entry
N: explicitly specifies an Encoding of UTF-8, which is harmless but no
N: longer necessary.
N:
N: Refer to
N: http://standards.freedesktop.org/desktop-entry-spec/1.0/apc.html for
N: details.

Thanks,
Ryan