Revert "Allow customizations to Roundcube settings to persist between updates by including a configuration override file, if it exists (#2333)"

This reverts commit 1b8cdeb644.

It didn't execute. I should have tried it first.

setup/webmail.sh

@@ -145,9 +145,6 @@ cat > $RCM_CONFIG <<EOF;
 \$config['session_path'] = '/mail/';
 /* prevent CSRF, requires php 7.3+ */
 \$config['session_samesite'] = 'Strict';
-/* Persist Customizations */
-\$file = __DIR__.'/config_override.inc.php';
-\if(file_exists($file)) { include $file; }
 ?>
 EOF
 
@@ -169,9 +166,6 @@ cat > ${RCM_PLUGIN_DIR}/carddav/config.inc.php <<EOF;
 	 'preemptive_auth' => '1',
 	 'hide'        =>  false,
 );
-/* Persist Customizations */
-\$file = __DIR__.'/config_override.inc.php';
-\if(file_exists($file)) { include $file; }
 ?>
 EOF