Make HAR files compatible with Firefox DevTools (#5666)
Make HAR files compatible with Firefox DevTools (#5666)

Firefox Developer Tools reject to load HAR files that do not have
`har.log.pages` element (see
<https://bugzilla.mozilla.org/show_bug.cgi?id=1691240>). Adding a
placeholder entry fixes it.

Co-authored-by: Maciej Zielenkiewicz <bec5fe2c1051b965f95e4f6982a054dfb9c282fe@connectpoint.pl>
mhils/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy