fix gpu ci script

tools/serving_build.sh

@@ -270,6 +270,7 @@ function python_run_criteo_ctr_with_cube() {
 function python_test_bert() {
     # pwd: /Serving/python/examples
     local TYPE=$1
+    yum install -y libXext libSM libXrender >/dev/null
     pip install ujson
     export SERVING_BIN=${SERVING_WORKDIR}/build-server-${TYPE}/core/general-server/serving
     cd bert # pwd: /Serving/python/examples/bert