PgpPublicKey.RemoveCert can delete wrong items.

[tohidemyname]

The code is as follows:

' private static PgpPublicKey RemoveCert(PgpPublicKey key, IUserDataPacket id)
{
PgpPublicKey returnKey = new PgpPublicKey(key);
bool found = false;

 for (int i = 0; i <returnKey.ids.Count-1; i++) 
 {
     if (id.Equals(returnKey.ids[i]))
     {
         found = true;
         returnKey.ids.RemoveAt(i);
         returnKey.idTrusts.RemoveAt(i);
         returnKey.idSigs.RemoveAt(i);
     }
 }

 return found ? returnKey : null;

}'
If returnKey.ids has more than one item, the first deletion will change the indexes of returnKey.*. The follow-up deletions will delete wrong items.
My pull request is as follows:

#545