TootComposer: don't switch the random placeholder

package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package",
   "name": "tutu",
-  "version": "1.0.7",
+  "version": "1.0.8",
   "description": "",
   "private": true,
   "type": "module",

src/timelines/TootComposer.tsx

@@ -1,5 +1,6 @@
 import {
   createEffect,
+  createMemo,
   createSignal,
   createUniqueId,
   onMount,
@@ -212,6 +213,10 @@ const TootComposer: Component<{
   const [langPickerOpen, setLangPickerOpen] = createSignal(false);
   const appLanguage = useLanguage();
 
+  const randomPlaceholder = createMemo(() =>
+    randomChoose(Math.random(), ["What's happening?", "What do your think?"]),
+  );
+
   createEffect(() => {
     const lang = appLanguage().split("-")[0];
     setLanguage(lang);
@@ -311,10 +316,7 @@ const TootComposer: Component<{
           placeholder={
             props.replyToDisplayName
               ? `Reply to ${props.replyToDisplayName}...`
-              : randomChoose(Math.random(), [
-                  "What's happening?",
-                  "What do your think?",
-                ])
+              : randomPlaceholder()
           }
           style={{ width: "100%", border: "none" }}
           disabled={sending()}