Don't show album creation button for non-admins.

controllers/ViewPhotoAlbum.php

@@ -57,16 +57,23 @@ class ViewPhotoAlbum extends HTMLController
 		if (isset($header_box))
 			$this->page->adopt($header_box);
 
-		$this->page->adopt(new AlbumButtonBox([
-			[
+		// Can we do fancy things here?
+		// !!! TODO: permission system?
+		$buttons = [];
+		if (Registry::get('user')->isLoggedIn())
+			$buttons[] = [
 				'url' => BASEURL . '/uploadmedia/?tag=' . $id_tag,
 				'caption' => 'Upload new photos here',
-			],
-			[
+			];
+		if (Registry::get('user')->isAdmin())
+			$buttons[] = [
 				'url' => BASEURL . '/addalbum/?tag=' . $id_tag,
 				'caption' => 'Create new subalbum here',
-			]
-		]));
+			];
+
+		// Enough actions for a button box?
+		if (!empty($buttons))
+			$this->page->adopt(new AlbumButtonBox($buttons));
 
 		// Fetch subalbums, but only if we're on the first page.
 		if ($page === 1)