Make naming of encryption app consistent

Fixes https://github.com/owncloud/core/issues/13580

apps/files_encryption/templates/settings-admin.php

+<?php
+	/** @var array $_ */
+	/** @var OC_L10N $l */
+?>
 <form id="encryption" class="section">
-	<h2><?php p($l->t('Encryption')); ?></h2>
+	<h2><?php p($l->t('Server-side Encryption')); ?></h2>
 
 	<?php if($_["initStatus"] === \OCA\Files_Encryption\Session::NOT_INITIALIZED): ?>
 		<?php p($l->t("Encryption App is enabled but your keys are not initialized, please log-out and log-in again")); ?>

apps/files_encryption/templates/settings-personal.php

+<?php
+	/** @var array $_ */
+	/** @var OC_L10N $l */
+?>
 <form id="encryption" class="section">
-	<h2><?php p( $l->t( 'Encryption' ) ); ?></h2>
+	<h2><?php p($l->t('Server-side Encryption')); ?></h2>
 
 	<?php if ( $_["initialized"] === \OCA\Files_Encryption\Session::NOT_INITIALIZED ): ?>