Reinstate a missing free.

In commit 869ce8867 I sank an sfree(fingerprint) into an if statement
that had previously been before it - but I only put it in two of the
three branches of the if. Now added it in the third one, preventing a
minor memory leak if you use SSH-1 with the -hostkey option (and the
actual host key presented by the server matches it).

ssh1login.c

@@ -252,6 +252,7 @@ static void ssh1_login_process_queue(PacketProtocolLayer *ppl)
                 return;
             }
         } else {
+            sfree(fingerprint);
             sfree(keystr);
         }
     }