M news_edit_page.php

• Removed the do not use double quotes string.

M lang/strings_english.txt

• Removed $s_do_not_use since it is no longer used. I am hoping the languages
  script deletes strings in other languages but not in English.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1892 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9