build - fix issue with secret_key substitution in tracker config.

The build system replaces the tracker config's etag key with a static
value to prevent churn every time the config is built.

The replacement wasn't working because of a missing character in the regexp.

Author: rouilj

doc/format_config.awk

@@ -6,8 +6,8 @@ NR < 9 {next}
 
 # To prevent new file generation from causing the secret_key to
 # change, we replace the secret key with a fixed value.
-/^# Default: [0-9A-z+=]{44}/ {sub(/[0-9A-z+=]{44}/, SECRET_KEY)}
-/^secret_key = [0-9A-z+=]{44}/ {sub(/[0-9A-z+=]{44}/, SECRET_KEY)}
+/^# Default: [0-9A-z+=/]{44}/ {sub(/[0-9A-z+=/]{44}/, SECRET_KEY)}
+/^secret_key = [0-9A-z+=/]{44}/ {sub(/[0-9A-Za-z+=/]{44}/, SECRET_KEY)}
 
 # When we see a section [label]:
 #  emit section index marker,