MB-28285: Bump the minimum required filedescriptors to 1k in engine_testapp
MB-28285: Bump the minimum required filedescriptors to 1k in engine_testapp

MacOSX use a default soft limit of 256 files, which is too few
for some of the rocksdb unit tests. Try to set the max limit to
at least 1k before starting unit tests.

Change-Id: Ib56943f38ff91600d3205c9c71183215140d7697
Reviewed-on: http://review.couchbase.org/89792
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Paolo Cocchi <9dd88c9f3e5cbab6e19a6c020f107e0c648ac956@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine