doc ja: fix a typo in reporter
doc ja: fix a typo in reporter

orz...

naoa/mroonga,naoa/mroonga,yoku0825/mroonga,naoa/mroonga,yoku0825/mroonga,naoa/mroonga,mroonga/mroonga,mroonga/mroonga,mroonga/mroonga,yoku0825/mroonga,naoa/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,naoa/mroonga,mroonga/mroonga