issue2551196 - Unset labelprop of a Multilink can lead to Python error when using context/history Fix history by adding default string value to calls to link_class.get(). Mark as translatable string. Include originally identified multilink path and apply same fix to link path. Also fix a possible issue in the plain() display paths for link/multilink the same way if the label is missing. Update translation files.

try:
    from html import escape as html_escape_  # python 3

    def html_escape(str, quote=False):
        # html_escape under python 3 sets quote to true by default
        # make it python 2 compatible
        return html_escape_(str, quote=quote)
except ImportError:
    # python 2 fallback
    from cgi import escape as html_escape  # noqa: F401