stabilize b40.vtc

seen in vtest:

**   l1    Waiting for logexp
**** dT    1.477
**** l1    match|       1016 BogoHeader      c Missing header name: : Header
***  l1    expecting| expect * 1018 VCL_Error Bad header foo:

/9 overtook /8

bin/varnishtest/tests/b00040.vtc

@@ -99,6 +99,7 @@ client c1 {
 	rxresp
 	expect resp.status == 400
 } -run
+delay .1
 
 client c1 {
 	txreq -url /9