Avoid fatal faults if volume stats are invalid

Returns garbage data, but avoids causing the entire API call to fail if
this happens on very old clusters (or after any sort of ZK corruption).

daemon-common/ceph.py

@@ -555,9 +555,16 @@ def getCephVolumes(zkhandler, pool):
 def getVolumeInformation(zkhandler, pool, volume):
     # Parse the stats data
     volume_stats_raw = zkhandler.read(("volume.stats", f"{pool}/{volume}"))
+    try:
         volume_stats = dict(json.loads(volume_stats_raw))
         # Format the size to something nicer
         volume_stats["size"] = format_bytes_tohuman(volume_stats["size"])
+    except Exception:
+        volume_stats = dict(
+            json.loads(
+                f'{"name":"{volume}","id":"","size":0,"objects":0,"order":0,"object_size":0,"snapshot_count":0,"block_name_prefix":"","format":0,"features":[],"op_features":[],"flags":[],"create_timestamp":"","access_timestamp":"","modify_timestamp":""}'
+            )
+        )
 
     volume_information = {"name": volume, "pool": pool, "stats": volume_stats}
     return volume_information