can-lehmann#88 minor adjustment to callback parameters

This doesn't really make it all that batter, it still segfaults
if you do anything, but at least this is more according to the docs.
No idea how to fix it.

owlkettle/adw.nim

@@ -732,7 +732,7 @@ when AdwVersion >= (1, 4):
         state.internalWidget = adw_spin_row_new(GtkAdjustment(nil), climbRate.cdouble, digits.cuint)
 
       connectEvents:        
-        proc changedCallback(widget: GtkWidget, data: ptr EventObj[proc (newValue: float)]) {.cdecl.} =
+        proc changedCallback(widget: GtkWidget, newValueHolder: ptr cdouble, data: ptr EventObj[proc (newValue: float)]) {.cdecl.} =
           echo "Changed Signal"
           var newValue: float
           try: