use set -u to catch uninitialized variables

diff --git a/letsencrypt.sh b/letsencrypt.sh
index edacf3659fbe7e210aa617b5faf4fb331cc7df56..8e6e2315398ef031c6d73f943af16985da2ad4e6 100755 (executable)
--- a/letsencrypt.sh
+++ b/letsencrypt.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -e
+set -eu
 
 . ./config.sh