Add default behaviour for configure / remove ext

See https://github.com/FreshRSS/FreshRSS/issues/252

app/Controllers/extensionController.php

@@ -130,6 +130,11 @@ class FreshRSS_extension_Controller extends Minz_ActionController {
 	}
 
 	public function removeAction() {
-		
+		if (!FreshRSS_Auth::hasAccess('admin')) {
+			Minz_Error::error(403);
+		}
+
+		$url_redirect = array('c' => 'extension', 'a' => 'index');
+		Minz_Request::bad('not implemented yet!', $url_redirect);
 	}
 }

app/views/extension/configure.phtml

@@ -0,0 +1,12 @@
+<?php
+
+if (!Minz_Request::param('ajax')) {
+	$this->partial('aside_configure');
+}
+
+?>
+
+<div class="post">
+	<h1>Extension name</h1>
+	Not implemented yet!
+</div>