general: remove (void) function parameter declarations

To my understanding, declaring empty parameter lists using "(void)"
is an artifact from the bad old K&R times, when functions were
declared without(!) parameters. Which in hindsight was an absolute
recipe for disaster. So for backwards compatibility, functions
without parameters had to be declared using "(void)" as "()"
could also mean "any function".

That was 40 years ago. Meanwhile, C++ introduced references,
which made it a necessity to declare the function parameters.
So "(void)" is redundant and inconsistent in C++ code and
just makes no sense.

Remove it.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/subsurfacestartup.cpp

@@ -191,7 +191,7 @@ void parse_argument(const char *arg)
  * I guess Burma and Liberia should trigger this too. I'm too
  * lazy to look up the territory names, though.
  */
-void setup_system_prefs(void)
+void setup_system_prefs()
 {
 	const char *env;