fix issue related to the latest version of Pistache for supporting C++11

build/scripts/build_helper.smf

@@ -110,7 +110,7 @@ install_spdlog_from_git() {
 install_pistache_from_git() {
   if [ $1 -eq 0 ]; then
     read -p "Do you want to install Pistache ? <y/N> " prompt
-    OPTION=""
+    OPTION="-y"
   else
     prompt='y'
     OPTION="-y"
@@ -135,7 +135,7 @@ install_pistache_from_git() {
 
     git clone $GIT_URL
     git submodule update --init
-    cd pistache && git checkout master
+    cd pistache && git checkout e18ed9baeb2145af6f9ea41246cf48054ffd9907
     ret=$?;[[ $ret -ne 0 ]] && popd && return $ret
     mkdir _build && cd _build
     cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release ..