Fixed problem with invalid stratum difficulty for Quark, AnimeCoin and QubitCoin.

util.c

@@ -45,6 +45,8 @@
 #include "util.h"
 
 #define DEFAULT_SOCKWAIT 60
+#define DM_SELECT(x, y, z) (dm_mode == DM_BITCOIN ? x : (dm_mode == DM_QUARKCOIN ? y : z))
+extern enum diff_calc_mode dm_mode;
 
 bool successful_connect = false;
 static void keep_sockalive(SOCKETTYPE fd)
@@ -1642,7 +1644,7 @@ static bool parse_diff(struct pool *pool, json_t *val)
 {
 	double old_diff, diff;
 
-	diff = json_number_value(json_array_get(val, 0));
+	diff = json_number_value(json_array_get(val, 0)) * DM_SELECT(1, 256, 1);
 	if (diff == 0)
 		return false;