plugins types BUGFIX leafref can match several data nodes

Fixes sysrepo/sysrepo#2930
diff --git a/src/plugins_types.c b/src/plugins_types.c
index 6d83ca7..67f1cdd 100644
--- a/src/plugins_types.c
+++ b/src/plugins_types.c
@@ -1005,8 +1005,7 @@
 
     /* check the result */
     if (target_path) {
-        /* no or exact match */
-        assert(!set.used || (set.used == 1));
+        /* no or exact match(es) */
         i = 0;
     } else {
         /* check whether any matches */