Revert "Allow auto_capture to be configured"

This commit is no longer needed with configurable auto_capture now a part of Spree.

https://github.com/spree/spree/commit/2609acb749a26690cf754124aaac470c2b205b2c

This reverts commit 9f11f98753c1c9e9dbee60d186b60db62e7fa3d8.