Update 'doc/.tx/config' - Build #37

  http://cookingwithsalt.org/job/salt/job/transifex/37/

Signed-off-by: Pedro Algarvio <pedro@algarvio.me>
Merge pull request #12452 from s0undt3ch/hotfix/transifex-updates

Update 'doc/.tx/config' - Build #37
Replace string substitution with string formatting
Replace string substitution with string formatting