Revert "build: remove references to WITH_YAJL for SETUID_RPC_CLIENT"

This reverts commit 1caf8441.

Jansson cannot parse QEMU's quirky JSON.
Revert back to yajl.

https://bugzilla.redhat.com/show_bug.cgi?id=1614569Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

config-post.h

@@ -44,6 +44,8 @@
 # undef WITH_SSH2
 # undef WITH_SYSTEMD_DAEMON
 # undef WITH_VIRTUALPORT
+# undef WITH_YAJL
+# undef WITH_YAJL2
 #endif
 
 /*