Markdown injection

[nijel]

Reported by Emanuel Bronshtein:

Markdown injection
in:
https://github.com/phpmyadmin/scripts/blob/master/phpmyadmin-reports#L144
https://github.com/phpmyadmin/scripts/blob/master/phpmyadmin-reports#L144
commit message & issue title are inserted into markdown link text context without escaping.
sample injection:
A](https://phishing.com) [t

fix:
escape needed chars:
\ ]
in order to avoid the injection.