Use HTTP POST to retrieve the list of contacts

We do not want to have sensitive information in the URL and
therefore also not in the access log. Thus the GET request is
replaced by a POST request.

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

core/js/contactsmenu.js

@@ -476,7 +476,7 @@
 		_getContacts: function(searchTerm) {
 			var url = OC.generateUrl('/contactsmenu/contacts');
 			return Promise.resolve($.ajax(url, {
-				method: 'GET',
+				method: 'POST',
 				data: {
 					filter: searchTerm
 				}

core/routes.php

@@ -57,7 +57,7 @@ $application->registerRoutes($this, [
 		['name' => 'Preview#getPreview', 'url' => '/core/preview.png', 'verb' => 'GET'],
 		['name' => 'Css#getCss', 'url' => '/css/{appName}/{fileName}', 'verb' => 'GET'],
 		['name' => 'Js#getJs', 'url' => '/js/{appName}/{fileName}', 'verb' => 'GET'],
-		['name' => 'contactsMenu#index', 'url' => '/contactsmenu/contacts', 'verb' => 'GET'],
+		['name' => 'contactsMenu#index', 'url' => '/contactsmenu/contacts', 'verb' => 'POST'],
 	],
 	'ocs' => [
 		['root' => '/cloud', 'name' => 'OCS#getCapabilities', 'url' => '/capabilities', 'verb' => 'GET'],