c-hyper: convert HYPERE_INVALID_PEER_MESSAGE to CURLE_UNSUPPORTED_PROTOCOL

Makes test 129 work (HTTP/1.2 response).

Closes #7141
diff --git a/lib/c-hyper.c b/lib/c-hyper.c
index b6654f5..be4618e 100644
--- a/lib/c-hyper.c
+++ b/lib/c-hyper.c
@@ -318,6 +318,8 @@
         failf(data, "Hyper: [%d] %.*s", (int)code, (int)errlen, errbuf);
         if((code == HYPERE_UNEXPECTED_EOF) && !data->req.bytecount)
           result = CURLE_GOT_NOTHING;
+        else if(code == HYPERE_INVALID_PEER_MESSAGE)
+          result = CURLE_UNSUPPORTED_PROTOCOL; /* maybe */
         else
           result = CURLE_RECV_ERROR;
       }