start_mock.bat - don't insert lone quotes

Change-Id: I911db0992116b794c9a4362827bcd459a8040596
Reviewed-on: http://review.couchbase.org/28121
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>