Remove repeated dictionary key 'matomo_site_id' from ui_common.py

[jsjiang]

Flake8 reported F601 dictionary key 'matomo_site_id' repeated with different values in two places in ui_common.py. If thematomo_site_id key is used by the Matomo API tracking, it will be removed when we clean up related code. If it is used by the UI, then remove the duplicated configuration.

def render(request, template, context={}):
    ctx = {
        "session": request.session,
        "authenticatedUser": impl.userauth.getUser(request),
        # Todo: Reimplement alertMessage without ServerVariables
        "alertMessage": None,
        "feed_cache": [],  # ezidapp.management.commands.newsfeed.getLatestItems(),
        "matomo_site_id": django.conf.settings.MATOMO_SITE_ID,
        "debug": django.conf.settings.DEBUG,
        "matomo_site_url": django.conf.settings.MATOMO_SITE_URL,
        "matomo_site_id": django.conf.settings.MATOMO_SITE_ID,
    }

def error(request, code, content_custom=None):
    ctx = {
        "menu_item": "ui_home.null",
        "session": request.session,
        # Todo: Reimplement alertMessage without ServerVariables
        "alertMessage": None,
        "feed_cache": [],  # ezidapp.management.commands.newsfeed.getLatestItems(),
        "matomo_site_id": django.conf.settings.MATOMO_SITE_ID,
        "content_custom": content_custom,
        "matomo_site_url": django.conf.settings.MATOMO_SITE_URL,
        "matomo_site_id": django.conf.settings.MATOMO_SITE_ID,
    }