Configure Meld Encoding to GBK

Get current setting for Meld

$ gsettings get org.gnome.meld detect-encodings
['utf8']

Add GBK to setting

$ gsettings set org.gnome.meld detect-encodings "['utf8', 'gbk']"

Get current setting for Meld

$ gsettings get org.gnome.meld detect-encodings
['utf8', 'gbk']