fixtures: hotfix dataset loading

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
41:1: E302 expected 2 blank lines, found 1
45:5: F401 'cli_cmd_reset_sitename' imported but unused
45:5: F401 'cli_cmd_reset_fieldnames' imported but unused
45:5: F401 'cli_cmd_reset_siteadminemail' imported but unused
48:5: F841 local variable 'conf' is assigned to but never used
61:13: F821 undefined name 'sys'
181:9: F401 'customize_app' imported but unused