Use uint32_t for ui Arg

dwl.c

@@ -82,7 +82,7 @@ enum { NetWMWindowTypeDialog, NetWMWindowTypeSplash, NetWMWindowTypeToolbar,
 
 typedef union {
 	int i;
-	unsigned int ui;
+	uint32_t ui;
 	float f;
 	const void *v;
 } Arg;