[PATCH] Add missing prototype in gdbtk.c

[Roland Schwingel]

Hi ...

"Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr> wrote on 30.03.2012 
15:02:30:
 > In fact, the same error also appears when
 > trying to compile a mingw32 version.
 >
 > I hope that I found the reason:
 > Prototypes apparently require (void) instead of ().
 >
 > The following patch fixes the problem for mingw32,
 >
 > Is this patch OK?
Ah yes that's it. I got the error and thought that there would be no
prototype at all. Work here now too and so obsoletes my patch.

Roland