Bug 29565: Prevent regressions.t to fail on slow boxes

Bug 29565: Prevent regressions.t to fail on slow boxes

It's failing randomly on some Jenkins' nodes

 #   Failed test 'Encoding in session variables'
 #   at t/db_dependent/selenium/regressions.t line 300.
 Can't call method "get_text" on an undefined value at t/db_dependent/selenium/regressions.t line 285.

It can be recreated locally with the following changes:
@ t/lib/Selenium.pm:50 @ sub new {
     );
     bless $self, $class;
     $self->add_error_handler;
-    $self->driver->set_implicit_wait_timeout(5000);
+    $self->driver->set_implicit_wait_timeout(1000);
     return $self;
 }

@ t/lib/Selenium.pm:50 @ sub new {
     );
     bless $self, $class;
     $self->add_error_handler;
-    $self->driver->set_implicit_wait_timeout(5000);
+    $self->driver->set_implicit_wait_timeout(1000);
     return $self;
 }

This patch suggests to simply double the timeout.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>