Fix 0003724: Problems with deleting a project.

M core/projects_api.php

• Disabling email_notifications before deleting project bugs, news, ...etc then reverting it back to its original value.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2497 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9