Adapt CustomTarget_postprocess/check_dynamic_objects to --enable-mergelibs=more

...which, after recent changes, failed now with

> [CHK] CustomTarget/postprocess/check_dynamic_objects/check.done
> instdir/program/libmergedlo.so has suspicious NEEDED: libgssapi_krb5.so.2
> instdir/program/libmergedlo.so has suspicious NEEDED: libcom_err.so.2
> instdir/program/libmergedlo.so has suspicious NEEDED: libkrb5.so.3

Change-Id: I80de1dd85f06d0e27b73355def68da9df2f6c2cd
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/164606
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>

bin/check-elf-dynamic-objects

@@ -198,7 +198,7 @@ local file="$1"
             fi
         ;;
         */libmergedlo.so)
-            allowlist="${allowlist} ${x11allowlist} ${openglallowlist} ${gioallowlist} ${dconfallowlist} libcups.so.2 libcairo.so.2"
+            allowlist="${allowlist} ${x11allowlist} ${openglallowlist} ${gioallowlist} ${kerberosallowlist} ${dconfallowlist} libcups.so.2 libcairo.so.2"
         ;;
     esac
     if test "${skip}" = 0 && readelf -d "${file}" &> /dev/null ; then