incorrect libpq comment

Bruce's commit 5d305d86bd917723f09ab4f15c075d90586a210a back in April
of 2014 includes this change:
    /* See PQconnectPoll() for how we use 'int' and not 'pgsocket'. */
-    int         sock;           /* Unix FD for socket, -1 if not connected */
+    pgsocket    sock;           /* FD for socket, PGINVALID_SOCKET if
unconnected */

I suppose Bruce must have overlooked the fact that the comment on the
previous line is now false.  I think we should remove it, because it
makes no sense to say how we are using 'int' rather than 'pgsocket'
when in fact we are not using 'int' any more.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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