Fix a copy-paste goof in a Pageant error message.

I never noticed before because it only comes up in the case of an
agent sending back one particular kind of corrupt data, but if the
last-minute check that there's no trailing junk on the end of the
agent's SSH-2 key list fails, it prints an error message erroneously
mentioning SSH-1.

pageant.c

@@ -1742,7 +1742,7 @@ int pageant_enum_keys(pageant_key_enum_fn_t callback, void *callback_ctx,
     sfree(keylist);
 
     if (keylistlen != 0) {
-        *retstr = dupstr("Received broken SSH-1 key list from agent");
+        *retstr = dupstr("Received broken SSH-2 key list from agent");
         return PAGEANT_ACTION_FAILURE;
     }