zabbix/borg: Force scalar context for borg output

This ensure compatability with JSON::PP which accepts a list rather than
only a single argument.
Signed-off-by: Florian Pritz <bluewind@xinu.at>

roles/zabbix-agent/files/zabbix-borg-timestamps.pl

@@ -6,7 +6,7 @@ use autodie;
 use JSON::XS;
 use POSIX;
 
-my $json = decode_json(`sudo /usr/local/bin/borg list --json --format '{start}{end}' --sort-by timestamp --last 1`);
+my $json = decode_json(scalar(`sudo /usr/local/bin/borg list --json --format '{start}{end}' --sort-by timestamp --last 1`));
 print encode_json({
 		last_archive => {
 			is_checkpoint => $json->{archives}[0]->{archive} =~ m/.checkpoint$/ ? 1 : 0,

roles/zabbix-agent/tasks/main.yml

@@ -4,7 +4,7 @@
   pacman: name=zabbix-agent,python-dbus
 
 - name: install packages for borg monitoring
-  pacman: name=perl-json-xs
+  pacman: name=perl-json
   when: "'borg-clients' in group_names"
 
 - name: install packages for nginx monitoring