Description of problem:
Zanata does not count symbols as words. Usually it is expected behavior.

However, String#40 in GNU Tar 1.27.1 contains a standalone '`'.
This entry trigger the inconsistent among word-based and msg-based statistics.

If translator miss the string, she might still see the statistics is 100%, yet the project maintainer who use msg statistics see only 50% translated.

Version-Release number of selected component (if applicable):
Zanata 3.6.0-SNAPSHOT (git-jenkins-zanata-server-github-pull-requests-2317) 

How reproducible:
Always

Steps to Reproduce:
1. Create a project (symbol) and  version (master), project type gettext
2. Upload the attached symbol.pot
3. Go to the translation editor
4. Translate the second string "no symbol"

Actual results:
Word-based statistics: 100%
Msg-based statistics: 50%

Expected results:
Word-based statistics: 2/3
Msg-based statistics: 50%


Additional info: