Fix test: en_eff wordlist now appears in help.

tests/exp_help_output.txt

@@ -21,8 +21,9 @@ optional arguments:
                         `realdice', `system'. Default: system
   -w NAME, --wordlist NAME
                         Use words from this wordlist. Possible values: `en',
-                        `en_orig', `en_securedrop'. Wordlists are stored in
-                        the folder displayed below. Default: en_securedrop
+                        `en_eff', `en_orig', `en_securedrop'. Wordlists are
+                        stored in the folder displayed below. Default:
+                        en_securedrop
   -v, --verbose         Be verbose. Use several times for increased verbosity.
   --version             output version information and exit.