tx: add deserialize to locktime/version properties (#6633)

electrum/transaction.py

@@ -545,6 +545,7 @@ class Transaction:
 
     @property
     def locktime(self):
+        self.deserialize()
         return self._locktime
 
     @locktime.setter
@@ -555,6 +556,7 @@ class Transaction:
 
     @property
     def version(self):
+        self.deserialize()
         return self._version
 
     @version.setter