Fix test, but it's still broken.

regress/extra_delete.test

diff --git a/regress/extra_delete.test b/regress/extra_delete.test
index f99ec64..d8f21ff 100644
--- a/regress/extra_delete.test
+++ b/regress/extra_delete.test
@@ -1,7 +1,9 @@
 # delete extra field by index
 program modify
-args encrypt.zip delete_extra 0 2 cl get_extra_by_id 0 2345 0 c get_extra_by_id 0 2345 0 l
+args encrypt.zip get_extra_by_id 0 2345 0 c get_extra_by_id 0 2345 0 l delete_extra 0 0 cl get_extra_by_id 0 2345 0 c get_extra_by_id 0 2345 0 l
 file encrypt.zip encrypt_plus_extra.zip encrypt.zip
-return 1
+return 0
+stdout Extra field 0x0929: len 17, data 0x65787472616669656c64636f6e74656e74
+stdout Extra field 0x0929: len 17, data 0x65787472616669656c64636f6e74656e74
 stderr can't get extra field data for file at index 0, extra field id 2345, ef index 0, flags 512: No such file
 stderr can't get extra field data for file at index 0, extra field id 2345, ef index 0, flags 256: No such file