RDB version is no 4, because small hashes are now encoded as ziplists, so...

RDB version is no 4, because small hashes are now encoded as ziplists, so older versions of Redis will not understand this format.

src/rdb.c

@@ -616,7 +616,7 @@ int rdbSave(char *filename) {
     }
 
     rioInitWithFile(&rdb,fp);
-    if (rdbWriteRaw(&rdb,"REDIS0003",9) == -1) goto werr;
+    if (rdbWriteRaw(&rdb,"REDIS0004",9) == -1) goto werr;
 
     for (j = 0; j < server.dbnum; j++) {
         redisDb *db = server.db+j;
@@ -1023,7 +1023,7 @@ int rdbLoad(char *filename) {
         return REDIS_ERR;
     }
     rdbver = atoi(buf+5);
-    if (rdbver < 1 || rdbver > 3) {
+    if (rdbver < 1 || rdbver > 4) {
         fclose(fp);
         redisLog(REDIS_WARNING,"Can't handle RDB format version %d",rdbver);
         errno = EINVAL;