trigger: fix memory leak in command /trigger addinput

ChangeLog.adoc

@@ -35,6 +35,7 @@ Bug fixes::
   * irc: fix add of channel to autojoin option when joining a channel with a buffer still opened
   * relay: fix save of channels in autojoin option when JOIN and PART commands are received from an IRC relay client (issue #1771)
   * trigger: add `${buffer.notify} > 0` in conditions of default trigger "beep"
+  * trigger: fix memory leak in command `/trigger addinput`
 
 [[v3.5]]
 == Version 3.5 (2022-03-27)

src/plugins/trigger/trigger-command.c

@@ -720,6 +720,8 @@ trigger_command_trigger (const void *pointer, void *data,
             weechat_buffer_set (buffer, "input_pos", "13");
             free (input);
         }
+        if (items)
+            weechat_string_free_split (items);
         goto end;
     }