Bug 18403: Prevent Modifications.t to fail randomly

Bug 18403: Prevent Modifications.t to fail randomly

    #   Failed test 'pending_count() correctly returns 2 if filtered by library'
    #   at t/db_dependent/Koha/Patron/Modifications.t line 355.
    #          got: '0'
    #     expected: '2'

    #   Failed test 'pending_count() correctly returns 2'
    #   at t/db_dependent/Koha/Patron/Modifications.t line 360.
    #          got: '0'
    #     expected: '2'

    #   Failed test 'pending_count() correctly returns 1'
    #   at t/db_dependent/Koha/Patron/Modifications.t line 365.
    #          got: '0'
    #     expected: '1'
    # Looks like you failed 3 tests of 16.

 #   Failed test 'pending_count() and pending() tests'
 #   at t/db_dependent/Koha/Patron/Modifications.t line 374.
 # Looks like you failed 1 test of 6.
 [19:45:28] t/db_dependent/Koha/Patron/Modifications.t

The logged in patron did not have permissions to view patron's info from other branches.

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