changed instructions to switch branch

[JappeHallunken]

Let's use the G_DEV_BRANCH function, it will make life easier if you have no option to copy and paste the instruction.

[MichaIng]

But then the 3rd step is not required anymore. It updates right away, without the chance to generate a backup or so.

[JappeHallunken]

Ok so then just remove the 3rd step in the docs, since the function does dietpi-update -1 anyway?

G_DEV_BRANCH(){
		G_CHECK_ROOT_USER 1
		G_CONFIG_INJECT 'DEV_GITBRANCH=' "DEV_GITBRANCH=$1" /boot/dietpi.txt
		/boot/dietpi/dietpi-update -1
	}

Also the recommendation for making a back up is mentioned in the first step.

[MichaIng]

Ah right, so only step 3 needs to be removed and we are good.