Update the 10.1-RELEASE schedule to reflect 10.1-RC4 builds have
started, a day late (which is my fault).

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45890 c2e8774f-c49f-e111-b436-862b2bbc8956