Fix PHP8.0 detection (#4383)

The phpInsNewer variable is not set anymore, so that the JSON module is now always tried to be installed. Instead of checking for phpInsNewer to derive whether PHP was installed already, phpInsMajor is now checked. If it is set, PHP is installed already, and only if the major version is lower than 8, the JSON module can be installed.

Signed-off-by: MichaIng <micha@dietpi.com>

automated install/basic-install.sh

@@ -292,7 +292,7 @@ if is_command apt-get ; then
     # It's useful to separate this from Pi-hole, since the two repos are also setup separately
     PIHOLE_WEB_DEPS=(lighttpd "${phpVer}-common" "${phpVer}-cgi" "${phpVer}-sqlite3" "${phpVer}-xml" "${phpVer}-intl")
     # Prior to PHP8.0, JSON functionality is provided as dedicated module, required by Pi-hole AdminLTE: https://www.php.net/manual/json.installation.php
-    if [[ "${phpInsNewer}" != true || "${phpInsMajor}" -lt 8 ]]; then
+    if [[ -z "${phpInsMajor}" || "${phpInsMajor}" -lt 8 ]]; then
         PIHOLE_WEB_DEPS+=("${phpVer}-json")
     fi
     # The Web server user,