p2p exhibition to exibition connection

plugins/cia-post-types/includes/p2p-mappings.php

@@ -25,7 +25,7 @@ function register_all_one_offs() {
     register_connections_for('short', ['short', 'exhibition', 'event', 'object', 'guide', 'post', 'technique', 'publication']);
     register_connections_for('technique', ['technique', 'post', 'publication']);
     register_connections_for('guide', ['technique', 'exhibition', 'post', 'publication']);
-    register_connections_for('exhibition', ['technique', 'publication']);
+    register_connections_for('exhibition', ['exhibition','technique', 'publication']);
     register_connections_for('event', ['event', 'object', 'post', 'guide', 'technique', 'publication']);
     register_connections_for('episode', ['episode', 'object', 'guide', 'technique', 'publication']);
     register_connections_for('post', ['post']);