test: fix typo in box-luatest/gh_6794_recover_nonmatching_xlogs

Because of the typo, the test fails on my localhost like this:

  There is no test with name 'test_ignore_with_force_recovery'
    but hook 'after_test' is defined for it

(I use luatest installed with luarocks).

Follow-up #6794
Follow-up 8c8b7739
  ("recovery: fix recovering from 1.6 xlogs/snaps")