fix: bl_file diff when clear memory cache is enabled

multi_user/bl_types/bl_file.py

@@ -135,6 +135,9 @@ class BlFile(ReplicatedDatablock):
             file.close()
 
     def diff(self):
-        memory_size = sys.getsizeof(self.data['file'])-33
+        if self.preferences.clear_memory_filecache:
-        disk_size = self.instance.stat().st_size
+            return False
-        return memory_size == disk_size
+        else:
+            memory_size = sys.getsizeof(self.data['file'])-33
+            disk_size = self.instance.stat().st_size
+            return memory_size == disk_size