解决OpenWrt19.07打不开luci应用设置页的问题

OpenWrt升级到19.07之后，安装应用，在luci界面中打开设置页，经常会报这样的错：

Failed to execute cbi dispatcher target for entry ***.
The called action terminated with an exception:
/usr/lib/lua/luci/dispatcher.lua:938: module 'luci.cbi' not found:
	no field package.preload['luci.cbi']
	no file './luci/cbi.lua'
	no file '/usr/share/lua/luci/cbi.lua'
	no file '/usr/share/lua/luci/cbi/init.lua'
	no file '/usr/lib/lua/luci/cbi.lua'
	no file '/usr/lib/lua/luci/cbi/init.lua'
	no file './luci/cbi.so'
	no file '/usr/lib/lua/luci/cbi.so'
	no file '/usr/lib/lua/loadall.so'
	no file './luci.so'
	no file '/usr/lib/lua/luci.so'
	no file '/usr/lib/lua/loadall.so'
stack traceback:
	[C]: in function 'require'
	/usr/lib/lua/luci/dispatcher.lua:938: in function </usr/lib/lua/luci/dispatcher.lua:937>

其实是因为19.07缺少luci-compat这个组件，在ssh或luci后台安装即可：

opkg update
opkg install luci-compat