[Jenkins] Added OGS_BUILD_UTILS=ON to clang job.

scripts/jenkins/clang.groovy

@@ -8,7 +8,8 @@ node('docker') {
         '-DOGS_LIB_BOOST=System ' +
         '-DOGS_LIB_VTK=System ' +
         '-DOGS_ADDRESS_SANITIZER=ON ' +
-        '-DOGS_UNDEFINED_BEHAVIOR_SANITIZER=ON'
+        '-DOGS_UNDEFINED_BEHAVIOR_SANITIZER=ON ' +
+        '-DOGS_BUILD_UTILS=ON'
 
     stage 'Checkout (Clang)'
     dir('ogs') { checkout scm }