MB-7250:  revcert 9984cf468f4f6237b448e574e3399cc22f4d62b9

Temporarily undo change which added application signing to the
build.  When tested in a login session the build succeeds, but
when run by buildbot Xcode doesn't have access to the
key/cert/identity/provioning profile needed and the build fails
and exits with "User interaction is not allowed."

Change-Id: I78d294951f0e01187a94756ff24b00a570209c31
Reviewed-on: http://review.couchbase.org/24412
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>