update fixtures

Author: normanrz

fixture/zstd/codec.00/config.json

@@ -1,4 +1,4 @@
 {
     "id": "zstd",
-    "level": 1
+    "level": 0
 }

fixture/zstd/codec.07/config.json

@@ -1,5 +1,5 @@
 {
     "id": "zstd",
-    "level": 1,
+    "level": 0,
     "checksum": true
 }