Motivation for changes:

Currently manipulate processes rejected entries, which is problematic. I don't understand the reason for this in the first place.

For example, I want to use manipulate to replace title with imdb_name. Some entries don't have valid imdb metadata, which causes manipulate to crash when trying to set title to None. This could be solved by using required_field: imdb_name and setting plugin_priority for manipulate to lower than required_field but it doesn't work because manupulate will process rejected entries also. This causes the task to crash.

Detailed changes:

set manipulate to ignore rejected entries