asn1_lib.c: ASN1_put_object: Remove comment about "class 0".

asn1_lib.c: ASN1_put_object: Remove comment about "class 0".

ASN1_put_object() was preceded by the nonsensical comment:

  /*
   * class 0 is constructed constructed == 2 for indefinite length constructed
   */

This is the result of concatenating two sentences in 0f113f3ee4d by
automated reformatting.  The first sentence, "class 0 is constructed",
goes back to d02b48c63a, the import of SSLeay 0.8.1b.  Even in that
context, it made little sense; class 0 means "universal", not
constructed, and there is no special significance to class 0 in this
function in any case.

Therefore I have simply removed that first sentence.

CLA: trivial

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/14998)