Fix typo

main.js

@@ -142,7 +142,7 @@ function faceMorph(message) {
     if(Math.random() > probValue.value())
         return;
 
-    let imageAttachment = message.attachments.find(v => isImage(v.filename));
+    let imageAttachment = message.attachments.find(v => isValidImage(v.filename));
     processFaceSwap(message, imageAttachment.url).catch(err => console.log(`Failed to run faceapp because ${err}`));
 }