fix: sometime meta-ver file lost

tests/system-test/0-others/walRetention.py

@@ -109,11 +109,14 @@ class VNode :
         # load config
         tdLog.info(f' meta-ver file={metaFile}')
         if metaFile != "":
+            try:
                 jsonVer = jsonFromFile(metaFile)
                 metaNode = jsonVer["meta"]
                 self.snapVer  = int(metaNode["snapshotVer"])
                 self.firstVer = int(metaNode["firstVer"])
                 self.lastVer  = int(metaNode["lastVer"])
+            except Exception as e:
+                tdLog.info(f' read json file except.')
 
         # sort with startVer
         self.walFiles = sorted(self.walFiles, key=lambda x : x.startVer, reverse=True)