server : (webui) revert hacky solution from #11626 (#11634)

Author: ngxson

examples/server/public/index.html.gz

@@ -468,14 +468,9 @@ const mainApp = createApp({
       URL.revokeObjectURL(url);
     },
     async sendMessage() {
-      if (!this.inputMsg) return;
-
-      if (this.isGenerating) {
-        this.stopGeneration();
-        while (this.isGenerating) {
-          await new Promise((resolve) => setTimeout(resolve, 10));
-        }
-      }
+      // prevent sending empty message
+      // also allow typing the message while generating, but does not allow sending it (to match UX/UI behavior of other chat apps)
+      if (!this.inputMsg || this.isGenerating) return;
 
       const currConvId = this.viewingConvId;