Fix #438201 "Upgrading essential pkgs results in duplicated reqby entries"
Fix #438201 "Upgrading essential pkgs results in duplicated reqby entries"

Always remove reqby entries while upgrading "essential" packages.

--HG--
extra : convert_revision : xtraeme%40gmail.com-20091001053542-amaw61ib23hy453n

ebfe/xbps,ebfe/xbps,datenwolf/xbps,datenwolf/xbps,datenwolf/xbps,ebfe/xbps,stpx/xbps,stpx/xbps,stpx/xbps