BUILD: log: Fix compilation without SSL support

When compiled without SSL support, a variable is reported as not used by
GCC.

src/log.c: In function ‘sess_build_logline’:
src/log.c:2056:36: error: unused variable ‘conn’ [-Werror=unused-variable]
 2056 |                 struct connection *conn;
      |                                    ^~~~

This does not need to be backported.
1 file changed