message: Tweak manifest caching
diff: @@ -988,3 +988,15 @@ FileETag None
  Header unset Expires
  </IfModule>
  </FilesMatch>
  +
  +# Cache namifest
  +
  +<FilesMatch "manifest-webapp">
  + FileETag None
  + <IfModule mod_headers.c>
  + Header unset ETag
  + Header set Cache-Control "max-age=900"
  + Header set Vary "User-Agent"
  + Header unset Expires
  + </IfModule>
  +</FilesMatch>
  \ No newline at end of file
  