HPCC-27433 Fix LN internal build tag

When the LN images were being built, BUILD_TAG_OVERRIDE was
being left as the community version.

Signed-off-by: Jake Smith <jake.smith@lexisnexisrisk.com>

dockerfiles/buildall.sh

@@ -95,6 +95,7 @@ build_ml_images() {
 }
 
 if [[ -n "$BUILD_LN" ]]; then
+  set_tag "internal"
   GITHUB_TOKEN=${LNB_TOKEN}
   lnBuildTag=${BUILD_TAG/community_/internal_}
   build_image platform-build-ln ${BUILD_LABEL} ${lnBuildTag}