Fix backups total size computation when there's only one full

zabbix_scripts/check_backuppc_sudo

@@ -59,13 +59,13 @@ if ( $host ) {
       next if ( $backup->{type} !~ m/^full|incr$/ );
       if ( $backup->{type} eq "full" ) {
         $json->{full_size}     = $backup->{size};
-        $new_size_of_last_full = $backup->{sizeNew};
+        $new_size_of_last_full = $backup->{sizeNew} if $backup->{num} > 0;
       }
       # Push all the sizes in our data set to compute avg sizes
       # Exclude backup N°0 as it'll always have much more new data than normal backups
       # Also exclude if size is not defined. This can happen in BackupPC v3 when
       # the BackupPC_link process is waiting for the nightly to finish
-      $sizes->add_data($backup->{sizeNew}) unless ( $backup->{num} == 0 || !$backup->{sizeNew} );
+      $sizes->add_data($backup->{sizeNew}) if ( $backup->{num} > 0 && $backup->{sizeNew} );
       $json->{bkp}++;
     }
 
@@ -132,9 +132,9 @@ if ( $host ) {
       # Save the total size of the last full backup
       if ( $backup->{type} eq 'full' ) {
         $host_full_size             = $backup->{size};
-        $host_new_size_of_last_full = $backup->{sizeNew};
+        $host_new_size_of_last_full = $backup->{sizeNew} if $backup->{num} > 0;
       }
-      $host_new_size += $backup->{sizeNew} unless ( $backup->{num} == 0 || !$backup->{sizeNew} );
+      $host_new_size += $backup->{sizeNew} if ( $backup->{num} > 0 && $backup->{sizeNew} );
 
       $entity_total_new  += $backup->{sizeNew};
       $entity_total_comp += $backup->{sizeNewComp};