schemas: fix rsa_common.json otherPrimeInfos format

As described in doc/types.md and confirmed in the original generator src
these array items are BigInt format, not Hex.

Thanks to jpgoldberg for the report.

Author: cpu

schemas/rsa_common.json

@@ -42,7 +42,7 @@
             "type": "array",
             "items": {
               "type": "string",
-              "format": "Hex"
+              "format": "BigInt"
             }
           }
         }