Revert "Set jRCU by default"

This reverts commit 8f2cd31cd45e618c932729aaedbd9783d1770f5d.
Revert "port jRCU from 3.3 to 3.4"

This reverts commit cebcf25a807d3f8e28a78856f9e95cd8f5a6acce.