Move ser_set_rts/dtr to beggining of serial_setup

https://github.com/Hamlib/Hamlib/issues/1131

src/serial.c

@@ -290,6 +290,10 @@ int HAMLIB_API serial_setup(hamlib_port_t *rp)
 
     fd = rp->fd;
 
+    // Linux sets pins high so we force them low once
+    ser_set_rts(rp, 0);
+    ser_set_dtr(rp, 0);
+
     /*
      * Get the current options for the port...
      */
@@ -631,9 +635,6 @@ int HAMLIB_API serial_setup(hamlib_port_t *rp)
     term_backup->next = term_options_backup_head;
     term_options_backup_head = term_backup;
 
-    ser_set_rts(rp, 0);
-    ser_set_dtr(rp, 0);
-
     return (RIG_OK);
 }