gedit 没有preference项，使preference回归，并用命令行设置行号，解决centos7下中文乱码，text wrapping等问题

1. 最简单的，使preference选项回来：

gsettings set org.gnome.settings-daemon.plugins.xsettings overrides '@a{sv} {"Gtk/ShellShowsAppMenu": <int32 0>}'

2. 设置行号:

gsettings set org.gnome.gedit.preferences.editor display-line-numbers true

 3. 当前行高亮:

gsettings set org.gnome.gedit.preferences.editor highlight-current-line true

4. 解决centos7 gedit中文乱码的问题:

gsettings set org.gnome.gedit.preferences.encodings candidate-encodings "['GB18030', 'GB2312', 'GBK', 'UTF-8', 'BIG5', 'CURRENT', 'UTF-16']"