fix(nsis): properly handle Webview2 download return value (#11139)

port of #11131 to 2.x

.changes/bundler-nsis-webview2-success.md

@@ -0,0 +1,5 @@
+---
+"tauri-bundler": "patch:bug"
+---
+
+Fix NSIS installer failing to determine whether webview installer downloaded correctly or not.

crates/tauri-bundler/src/bundle/windows/nsis/installer.nsi

@@ -541,7 +541,7 @@ Section WebView2
         DetailPrint "$(webview2Downloading)"
         NSISdl::download "https://go.microsoft.com/fwlink/p/?LinkId=2124703" "$TEMP\MicrosoftEdgeWebview2Setup.exe"
         Pop $0
-        ${If} $0 = 0
+        ${If} $0 == "success"
           DetailPrint "$(webview2DownloadSuccess)"
         ${Else}
           DetailPrint "$(webview2DownloadError)"