ftp: make domore_getsock() return the secondary socket properly

Previously, after PASV and immediately after the data connection has
connected, the function would only return the control socket to wait for
which then made the data connection simply timeout and not get polled
correctly. This become obvious when running test 1631 and 1632 event-
based.

lib/ftp.c

@@ -816,6 +816,7 @@ static int ftp_domore_getsock(struct connectdata *conn, curl_socket_t *socks)
 
   if(FTP_STOP == ftpc->state) {
     int bits = GETSOCK_READSOCK(0);
+    bool any = FALSE;
 
     /* if stopped and still in this state, then we're also waiting for a
        connect on the secondary connection */
@@ -830,10 +831,11 @@ static int ftp_domore_getsock(struct connectdata *conn, curl_socket_t *socks)
         if(conn->tempsock[i] != CURL_SOCKET_BAD) {
           socks[s] = conn->tempsock[i];
           bits |= GETSOCK_WRITESOCK(s++);
+          any = TRUE;
         }
       }
     }
-    else {
+    if(!any) {
       socks[1] = conn->sock[SECONDARYSOCKET];
       bits |= GETSOCK_WRITESOCK(1) | GETSOCK_READSOCK(1);
     }