getServerByKey cannot report weight anymore

Due to a change in libmemcached (exposed in
5450f45), `getServerByKey` is not able
any more to report a server weight. It reports 0 instead. This makes the
test on this function fails. We fix this by expecting a weight of 0
instead of a weight of 1.

Author: Vincent Bernat

tests/experimental/getserverbykey.phpt

@@ -31,29 +31,29 @@ array(%d) {
   ["port"]=>
   int(%d)
   ["weight"]=>
-  int(1)
+  int(0)
 }
 array(%d) {
   ["host"]=>
   string(%d) "%s"
   ["port"]=>
   int(%d)
   ["weight"]=>
-  int(1)
+  int(0)
 }
 array(%d) {
   ["host"]=>
   string(%d) "%s"
   ["port"]=>
   int(%d)
   ["weight"]=>
-  int(1)
+  int(0)
 }
 array(%d) {
   ["host"]=>
   string(%d) "%s"
   ["port"]=>
   int(%d)
   ["weight"]=>
-  int(1)
+  int(0)
 }