...but for safety, leave the configure.ac check in for some longer.

Also remove now-redundant SAL_INLINE_VARIABLE again (which was
LIBO_INTERNAL_ONLY).

Change-Id: Id049e0cb84b4f97f5859f1b16b867b39b448dec0
Reviewed-on: https://gerrit.libreoffice.org/64772
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>