Create versions file before sourcing it

[yubiuser]

What does this PR aim to accomplish?:

We use /etc/pihole/versions to store version, branch and hash information of the Pi-hole components. This file is populated by updatechecker.sh. Other scripts source this file. Among them, is pihole itself.

pi-hole/pihole

Lines 26 to 27 in fe598a0

	versionsfile="/etc/pihole/versions"
	source "${versionsfile}"

During installation, we call updatecheck as one of the last functions.

pi-hole/automated install/basic-install.sh

Lines 2720 to 2724 in fe598a0

	# Download and compile the aggregated block list
	runGravity
	# Update local and remote versions via updatechecker
	/opt/pihole/updatecheck.sh

Right before, we run gravity, which itself uses a function provided by pihole, e.g.

pi-hole/gravity.sh

Line 994 in fe598a0

"${PIHOLE_COMMAND}" status

This is a issue on fresh installation, as /etc/pihole/versions won't exist yet, leading to errors

  [i] Number of regex whitelist filters: 0
/usr/local/bin/pihole: line 27: /etc/pihole/versions: No such file or directory
  [i] FTL is not running
  [✓] Cleaning up stray matter
/usr/local/bin/pihole: line 27: /etc/pihole/versions: No such file or directory
  [✓] Restarting DNS server

/usr/local/bin/pihole: line 27: /etc/pihole/versions: No such file or directory

How does this PR accomplish the above?:

Simply swap gravity run and updatechecker during the installation.

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[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/pi-hole-ftl-v5-20-1-web-v5-18-1-and-core-v5-15-released/60495/1

[yubiuser]

Well done.. only 20 days later I reverted this PR with #5137 without remembering I just changed it.