Update system-vc and fix get statistics with VC reference test.

Change-Id: I27a3c8e6a7f4c656006a58b39ff253c8e950fe9c
diff --git a/src/test/resources/vc/system-vc.jsonld b/src/test/resources/vc/system-vc.jsonld
index 4dbd606..2b3aaf0 100644
--- a/src/test/resources/vc/system-vc.jsonld
+++ b/src/test/resources/vc/system-vc.jsonld
@@ -1 +1 @@
-{"collection":{"@type":"koral:doc","value":"GOE","match":"match:eq","key":"corpusSigle"}}
\ No newline at end of file
+{"corpus":{"@type":"koral:doc","value":"1810","match":"match:geq","type":"type:date","key":"creationDate"}}
\ No newline at end of file