Added explicit 'void' to function that takes no argument

This is the correct way to tell that a function takes no
arguments, because an empty parameter list tells the compiler
that it is not yet defined, and is tolerated only for
compatibility with very old C compilers for whom prototypes
were not yet a defined language element.

src/defaults.c

@@ -753,7 +753,7 @@ WDefaultEntry optionList[] = {
 	    &wPreferences.cycle_ignore_minimized, getBool, NULL, NULL, NULL}
 };
 
-static void initDefaults()
+static void initDefaults(void)
 {
 	unsigned int i;
 	WDefaultEntry *entry;