Fix a logic error in connection_tls_continue_handshake().

(If we take the branch above this assertion, than we *didn't* have a
v1 handshake.  So if we don't take the branch, we did.  So if we
reach this assertion, we must be running as a server, since clients
no longer attempt v1 handshakes.)

Fix for bug 17654; bugfix on 9d019a7db7.

Bug not in any released Tor.

src/or/connection_or.c

@@ -1480,7 +1480,7 @@ connection_tls_continue_handshake(or_connection_t *conn)
           return 0;
         }
       }
-      tor_assert(!tor_tls_is_server(conn->tls));
+      tor_assert(tor_tls_is_server(conn->tls));
       return connection_tls_finish_handshake(conn);
     case TOR_TLS_WANTWRITE:
       connection_start_writing(TO_CONN(conn));