Remove Matthew Lijun as committer

Matthew Lijun moved to a new employer which is not a member to OPNFV
requiring Matthew to sign individual CLA. This has not happened over
the past weeks which needs us to take action to initiate committer
removal process.

Change-Id: I17081aaffae72e01e98814defe062accac0a4739
Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>