The column "is_in_chlog" in "trackers" table can be removed safely. It was used to control former Changelog view which has been dropped in r3162 (Redmine 0.9.0). After that, the column is no longer used.

$ grep -r is_in_chlog *
db/migrate/20180923091603_change_sqlite_booleans_default.rb:      "is_in_chlog" => false,
db/migrate/001_setup.rb:      t.column "is_in_chlog", :boolean, :default => false, :null => false
db/migrate/20180923082945_change_sqlite_booleans_to_0_and_1.rb:    Tracker => ['is_in_chlog', 'is_in_roadmap'],
lib/redmine/default_data/loader.rb:            Tracker.create!(:name => l(:default_tracker_bug),     :default_status_id => new.id, :is_in_chlog => true,  :is_in_roadmap => false, :position => 1)
lib/redmine/default_data/loader.rb:            Tracker.create!(:name => l(:default_tracker_feature), :default_status_id => new.id, :is_in_chlog => true,  :is_in_roadmap => true,  :position => 2)
lib/redmine/default_data/loader.rb:            Tracker.create!(:name => l(:default_tracker_support), :default_status_id => new.id, :is_in_chlog => false, :is_in_roadmap => false, :position => 3)
test/fixtures/trackers.yml:  is_in_chlog: true
test/fixtures/trackers.yml:  is_in_chlog: true
test/fixtures/trackers.yml:  is_in_chlog: false