Rejected example CVE Record is inconsistent with 4.5.3.7 in CNA Rules 4.0

Updated rejected example CVE Record to include a better rejectedReasons value. Fixes Issue #313

Author: ccoffin

schema/docs/cnaContainer-rejected-example.json

@@ -7,8 +7,8 @@
     "rejectedReasons": [
       {
         "lang": "en",
-        "value": "This CVE ID has been rejected or withdrawn by its CVE Numbering Authority."
+        "value": "This CVE Record has been rejected because it is a duplicate of CVE-1900-12345."
       }
     ]
   }
-}
+}