fix: ZFSPath.from_string

zfs-backup.py

@@ -88,8 +88,10 @@ class ZFSPath:
 
     @classmethod
     def from_string(cls, string: str) -> ZFSPath:
-        path, snapname = string.split("@")
-        elements: list[str] = path.split("/")
+        snapname = None
+        if "@" in string:
+            string, snapname = string.split("@")
+        elements: list[str] = string.split("/")
         return ZFSPath(elements, snapname)
 
     @property