Change a couple of cache hit rate to float type, to avoid unmarshal errors

Tested with: go test ./...

Author: sfc-gh-bxin

model.go

@@ -177,8 +177,8 @@ type Status struct {
 			Name        string `json:"name"`
 		} `json:"messages"`
 		PageCache struct {
-			LogHitRate     int `json:"log_hit_rate"`
-			StorageHitRate int `json:"storage_hit_rate"`
+			LogHitRate     float64 `json:"log_hit_rate"`
+			StorageHitRate float64 `json:"storage_hit_rate"`
 		} `json:"page_cache"`
 		Processes map[string]struct {
 			Address     string `json:"address"`

testdata/status2.json

@@ -511,8 +511,8 @@
       }
     ],
     "page_cache": {
-      "log_hit_rate": 1,
-      "storage_hit_rate": 1
+      "log_hit_rate": 0.99832799999999999,
+      "storage_hit_rate": 0.99840299999999993
     },
     "processes": {
       "05ab57c2b7cd6b51e62a1390da76217a": {