fixed documentation typo.
fixed documentation typo.

LesleyLai/cppunit,freedesktop-unofficial-mirror/libreoffice__cppunit,ryancalhoun/cppunit,freedesktop-unofficial-mirror/libreoffice__cppunit,ryancalhoun/cppunit,freedesktop-unofficial-mirror/libreoffice__cppunit,project-zerus/cppunit,project-zerus/cppunit,LesleyLai/cppunit,ryancalhoun/cppunit,LesleyLai/cppunit,project-zerus/cppunit,freedesktop-unofficial-mirror/libreoffice__cppunit,ryancalhoun/cppunit,LesleyLai/cppunit