codetools: identifier completion: fixed typo

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42040 4005530d-fff6-0310-9dd1-cebe43e6787f
codetools: fixed error message if include file name is empty

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42041 4005530d-fff6-0310-9dd1-cebe43e6787f