configure:     yajl: no
CC     libvirt_util_la-json.lo
util/json.c:32:27: error: yajl/yajl_gen.h: No such file or directory
util/json.c:33:29: error: yajl/yajl_parse.h: No such file or directory

* src/util/json.c: remove the includes if yajl not configured in