Remove extra leading [ from images

app/articles/2012/03/15/kersz-cukorkat.md

app/articles/2012/06/25/happy-ipv6-day.md

app/articles/2013/11/15/samsung-windows-8-tablet.md

app/articles/2013/11/15/tobb-php-verzio-iis-en.md

...016/07/11/securiteam-biztonsagi-alapozo-tanfolyam-2016.md

app/articles/2017/08/30/ip-igenyles-2017-osz.md

app/articles/2018/05/19/lezarult-a-2018-as-kszkepzes.md

app/articles/2018/06/15/klimat-kapott-a-kszk.md