Ignore commented lines when reading PRIVACYLEVEL from config file

[yubiuser]

What does this PR aim to accomplish?:

During updates, we extract PRIVACYLEVEL from /etc/pihole/pihole-FTL.conf and later set it again

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

Lines 2613 to 2619 in d86b325

	# Get the privacy level if it exists (default is 0)
	if [[ -f "${FTL_CONFIG_FILE}" ]]; then
	PRIVACY_LEVEL=$(sed -ne 's/PRIVACYLEVEL=\(.*\)/\1/p' "${FTL_CONFIG_FILE}")
	# If no setting was found, default to 0
	PRIVACY_LEVEL="${PRIVACY_LEVEL:-0}"
	fi

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

Line 1852 in d86b325

addOrEditKeyValPair "${FTL_CONFIG_FILE}" "PRIVACYLEVEL" "${PRIVACY_LEVEL}"

However, if /etc/pihole/pihole-FTL.conf contains a commented line containing PRIVACYLEVEL, setting it during update will fail because it did not ignore the commented line.

+ addOrEditKeyValPair /etc/pihole/pihole-FTL.conf PRIVACYLEVEL '#; 3
0'
+ local file=/etc/pihole/pihole-FTL.conf
+ local key=PRIVACYLEVEL
+ local 'value=#; 3
0'

This was reported here: #5174

How does this PR accomplish the above?:

Adding a sed to remove all commented lines from /etc/pihole/pihole-FTL.conf before extracting PRIVACYLEVEL

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[dschaper]

Can you squash to 1 commit and FP?

[yubiuser]

Done.