re-added accidentally removed LT_HAVE_INLINE define

in my commit 0ea54aed
"remove some unused defines"

Change-Id: I2d8d9242eda9f39e1f932b2d9849fefb57b196eb
Reviewed-on: https://gerrit.libreoffice.org/17496Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

i18nlangtag/source/languagetag/languagetag.cxx

@@ -26,6 +26,7 @@
 
 #if defined(ENABLE_LIBLANGTAG)
 #if LIBLANGTAG_INLINE_FIX
+#define LT_HAVE_INLINE
 #endif
 #include <liblangtag/langtag.h>
 #else