prevent php8 warnings, fixes #2215

Closes #2215

Merge request studip/studip!1445

app/views/admin/plugin/manifest.php

@@ -22,7 +22,7 @@
 
     <dt><?= _('Beschreibung') ?></dt>
     <dd>
-    <? if ($manifest['description']): ?>
+    <? if (!empty($manifest['description'])): ?>
         <?= htmlReady($manifest['description']) ?>
     <? else: ?>
         (<?= _('keine Beschreibung vorhanden') ?>)

app/views/calendar/schedule/entry.php

-<? if (!empty($show_entry) && in_array($show_entry['type'], ['sem', 'virtual']) !== false) : ?>
+<? if (!empty($show_entry) && in_array($show_entry['type'], ['sem', 'virtual'])): ?>
     <?= $this->render_partial('calendar/schedule/_entry_course.php') ?>
-    <? unset($this->show_entry) ?>
-<? elseif ($show_entry && $show_entry['type'] == 'inst') : ?>
+    <? unset($show_entry) ?>
+<? elseif (!empty($show_entry) && $show_entry['type'] === 'inst'): ?>
     <?= $this->render_partial('calendar/schedule/_entry_inst.php') ?>
-    <? unset($this->show_entry) ?>
+    <? unset($show_entry) ?>
 <? else : ?>
     <?= $this->render_partial('calendar/schedule/_entry_schedule.php') ?>
 <? endif ?>