Fix for --enable-debug --disable-assert-always-abort

...found by <https://ci.libreoffice.org/job/lo_tb_random_config_linux/1465/>

Change-Id: Ia38fe5cac9fa187535599d313a3422c34458bcd9
Reviewed-on: https://gerrit.libreoffice.org/60242
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

cppu/source/uno/check.cxx

@@ -256,7 +256,7 @@ static_assert(sizeof(second) == sizeof(int), "sizeof(second) != sizeof(int)");
 # error unexpected alignment of 8 byte types
 #endif
 
-#if OSL_DEBUG_LEVEL > 0
+#if OSL_DEBUG_LEVEL > 0 && !defined NDEBUG
 
 #define OFFSET_OF( s, m ) reinterpret_cast< size_t >(reinterpret_cast<char *>(&reinterpret_cast<s *>(16)->m) -16)