Fixes the following error due to strict_types being enabled:

PHP message: PHP Fatal error:  Uncaught TypeError: array_slice(): Argument #3
($length) must be of type ?int, string given

diff --git a/ui/app/partials/service.list.edit.php b/ui/app/partials/service.list.edit.php
index f761463..9bf13af 100644
--- a/ui/app/partials/service.list.edit.php
+++ b/ui/app/partials/service.list.edit.php
@@ -65,7 +65,7 @@ foreach ($data['services'] as $serviceid => $service) {
 	if ($data['is_filtered']) {
 		$parents = [];
 
-		foreach (array_slice($service['parents'], 0, $data['max_in_table']) as $parent) {
+		foreach (array_slice($service['parents'], 0, (int) $data['max_in_table']) as $parent) {
 			if ($parents) {
 				$parents[] = ', ';
 			}
@@ -82,7 +82,7 @@ foreach ($data['services'] as $serviceid => $service) {
 
 	$root_cause = [];
 
-	foreach (array_slice($service['problem_events'], 0, $data['max_in_table']) as $problem_event) {
+	foreach (array_slice($service['problem_events'], 0, (int) $data['max_in_table']) as $problem_event) {
 		if ($root_cause) {
 			$root_cause[] = ', ';
 		}
diff --git a/ui/app/partials/service.list.php b/ui/app/partials/service.list.php
index 4af0556..1ba799c 100644
--- a/ui/app/partials/service.list.php
+++ b/ui/app/partials/service.list.php
@@ -78,7 +78,7 @@ foreach ($data['services'] as $serviceid => $service) {
 
 	$root_cause = [];
 
-	foreach (array_slice($service['problem_events'], 0, $data['max_in_table']) as $problem_event) {
+	foreach (array_slice($service['problem_events'], 0, (int) $data['max_in_table']) as $problem_event) {
 		if ($root_cause) {
 			$root_cause[] = ', ';
 		}