pagure: Fix SHA256 hashes for pagure.io and stg.pagure.io
    
    In 4812bc39e (Add the SHA256 of the ssh key, 2016-05-28) the SHA256
    fingerprints were added to the wrong section.  The stg.pagure.io
    fingerprint is in the pagure.io section and vice versa.  The MD5
    fingerprints are correct.
    
    This can be confirmed by checking the output of ssh-keygen with the SSH
    pubkey values for each host:
    
        $ for i in {stg.,}pagure.io.pub; do echo $i; cat $i; for hash in sha256 md5; do ssh-keygen -l -E $hash -f $i; done; echo; done
        stg.pagure.io.pub
        ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDJNu490Rp305zGCJLvhVIrKjL7Xngew3NxgRYeopHBDvj+EFQUqULXtgrI5nUBMSB94RrsuHynFAXYy2m0snHjWzWjbIxM4ZVD2sX4GiKX6qu7WyxcGmGcL08MF919r+JSPL9oWWSq/CvvBF0M1eeqkIpjMZHpVKgR3uTMD5yW994NBLAQi9i1UdwGYNQc1KqWvlvW1XhFFtiIGscIFGRKsUOMvnJvWdU6T+djmzMy4hcahxnsPCZxCjbQpuH1JjihNNVWYOq7Ztjs1gxpTTV19ATp4Z2F95uyyQ3Y+Em9KeXcKXYxwVzYVho5SSB1ZYBL+xAH1osK23PvGD39UYp9
        2048 SHA256:x4xld/tPdeOhbyJcTOxd+IbSZ4OpnBzh/IskocyrOME stg.pagure.io.pub (RSA)
        2048 MD5:69:50:46:24:c7:94:44:f8:8d:83:05:5c:eb:73:fb:c4 stg.pagure.io.pub (RSA)
    
        pagure.io.pub
        ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC198DWs0SQ3DX0ptu+8Wq6wnZMrXUCufN+wdSCtlyhHUeQ3q5B4Hgto1n2FMj752vToCfNTn9mWO7l2rNTrKeBsELpubl2jECHu4LqxkRVihu5UEzejfjiWNDN2jdXbYFY27GW9zymD7Gq3u+T/Mkp4lIcQKRoJaLobBmcVxrLPEEJMKI4AJY31jgxMTnxi7KcR+U5udQrZ3dzCn2BqUdiN5dMgckr4yNPjhl3emJeVJ/uhAJrEsgjzqxAb60smMO5/1By+yF85Wih4TnFtF4LwYYuxgqiNv72Xy4D/MGxCqkO/nH5eRNfcJ+AJFE7727F7Tnbo4xmAjilvRria/+l
        2048 SHA256:Gddkd5H7oQ1RaK8WgXSKl7JZP+FgLyidmxbLercJ/JY pagure.io.pub (RSA)
        2048 MD5:90:8e:7f:a3:f7:f1:70:cb:56:77:96:17:44:c4:fc:82 pagure.io.pub (RSA)