Fix build error with MSVC 2015
Fix build error with MSVC 2015

Change-Id: I84df82e584be05f1b30717187ab506aeb5fbf190
Reviewed-on: http://review.couchbase.org/72251
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

mody/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,mody/libcouchbase,kojiromike/libcouchbase