fix: crash in member role change logging

Author: Dragory

backend/src/plugins/Logs/events/LogsGuildMemberRoleChangeEvt.ts

@@ -35,7 +35,7 @@ export const LogsGuildMemberRoleChangeEvt = guildPluginEventListener<LogsPluginT
     }
 
     const member = await pluginData.guild.members.fetch(auditLogEntry.targetId!);
-    const mod = await pluginData.client.users.fetch(auditLogEntry.executorId!);
+    const mod = auditLogEntry.executorId ? await pluginData.client.users.fetch(auditLogEntry.executorId) : null;
     for (const change of auditLogEntry.changes) {
       if (isRoleAddChange(change)) {
         const addedRoles = change.new.map((r) => resolveRole(pluginData.guild, r.id));