MB-9475:  2.5 READMEs for macosx, without trailing whitespace

Change-Id: I925c8a1ecbf144fea609f482828d747caccf38e4
Reviewed-on: http://review.couchbase.org/32696
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>