MB-37768: Don't override CMAKE_INSTALL_RPATH
MB-37768: Don't override CMAKE_INSTALL_RPATH

Change-Id: I1e894c43dfd70a190974e8d9bfb923b43283c142
Reviewed-on: http://review.couchbase.org/123497
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase