Bug 34655: Prevent selenium/system_preferences_search.t to fail randomly

Bug 34655: Prevent selenium/system_preferences_search.t to fail randomly

Removing this JS code from document.ready.
The script tag is at the end of the DOM and there is no good reasons (at
least I didn't find any) to wait for the whole document to be ready
before executing the JS code.

It made the selenium tests selenium/system_preferences_search.t to fail
randomly with:
    #   Failed test 'The first "Policy" section (under "Accounting") is currently expanded'
    #   at t/db_dependent/selenium/system_preferences_search.t line 63.
    #          got: undef
    #     expected: 'expanded'
    # Looks like you failed 1 test of 6.

Because we set the class in this JS code and selenium won't wait for it
to finish before starting running the tests.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>