fix(obnam.md): adapt to error message that has changed slightly

Signed-off-by: Lars Wirzenius <liw@liw.fi>
Sponsored-by: author

1 files changed, 1 insertions, 1 deletions

diff --git a/obnam.md b/obnam.md
index ef6daea..f7c0bbe 100644
--- a/obnam.md
+++ b/obnam.md
@@ -1448,7 +1448,7 @@ and a client config based on ca-required.yaml
 and a file live/data.dat containing some random data
 when I try to run obnam backup
 then command fails
-then stderr contains "self signed certificate"
+then stderr matches regex self.signed certificate
 ~~~
 
 ~~~{#ca-required.yaml .file .yaml .numberLines}