nixosTests.*: Don't use the `-q` flag with grep when used with curl

The `-q` flag makes grep close the pipe early, which curl doesn't
handle gracefully, but exits with an error like "(23) Failed writing
body".

1 files changed, 1 insertions, 1 deletions

diff --git a/nixos/tests/elk.nix b/nixos/tests/elk.nix
index fee350de65b..71d39a647a5 100644
--- a/nixos/tests/elk.nix
+++ b/nixos/tests/elk.nix
@@ -178,7 +178,7 @@ let
           one.systemctl("stop logstash")
           one.systemctl("start elasticsearch-curator")
           one.wait_until_succeeds(
-              '! curl --silent --show-error "${esUrl}/_cat/indices" | grep logstash | grep -q ^'
+              '! curl --silent --show-error "${esUrl}/_cat/indices" | grep logstash | grep ^'
           )
     '';
   }) {};