Bug 17911: Message and timeout mismatch

Bug 17911: Message and timeout mismatch

The installation step 3 has a meta refresh of 10 seconds,
but the message says 5 seconds. People could get impatient.

TEST PLAN
---------
1) Fresh install
   -- notice the discrepancy on the web installation.
2) drop and create the DB
3) apply the patch
4) run the web install
   -- notice it refreshes faster (5 seconds vs 10 seconds)
5) run koha qa test tools

Works as intended and passes qa test tool
 OK koha-tmpl/intranet-tmpl/prog/en/modules/installer/step3.tt
  OK    forbidden patterns
  OK     git manipulation
  OK      spelling
  OK   tt_valid
  OK    valid_template

Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>