Merge branch 'fix-file_env' into 'master'

Fixes displaying the wrong variable on error in file_env

See merge request ix.ai/smtp!12

Author: tlex

entrypoint.sh

@@ -8,10 +8,9 @@ set -e
 file_env() {
         local var="$1"
         local fileVar="${var}_FILE"
-        local varName="${!var@}"
         local def="${2:-}"
         if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
-                echo >&2 "error: both ${varName} and ${fileVar} are set (but are mutually exclusive)"
+                echo >&2 "error: both ${var} and ${fileVar} are set (but are mutually exclusive)"
                 exit 1
         fi
         local val="$def"