Catch ActivityNotFoundException when opening external WebView links

[jim-daf]

Closes #131.

What changes

WebUiActivity.kt's shouldOverrideUrlLoading calls startActivity(Intent(Intent.ACTION_VIEW, uri)) to hand off external links (Syncthing docs, forum, etc.) to a system browser. If no installed app can handle that intent, startActivity raises ActivityNotFoundException and the activity crashes.

This wraps the call in a try / catch (ActivityNotFoundException) and logs a warning. The click becomes a silent no-op instead of a crash, which is the standard outcome when there is no browser registered.

 override fun shouldOverrideUrlLoading(view: WebView, request: WebResourceRequest): Boolean {
     val uri = request.url
     val guiUri = guiUri

     if (uri.scheme == guiUri.scheme && uri.host == guiUri.host && uri.port == guiUri.port) {
         return false
     } else {
-        startActivity(Intent(Intent.ACTION_VIEW, uri))
+        try {
+            startActivity(Intent(Intent.ACTION_VIEW, uri))
+        } catch (e: ActivityNotFoundException) {
+            Log.w(TAG, "No app installed to handle $uri", e)
+        }
         return true
     }
 }

android.content.ActivityNotFoundException is added to the imports. Nothing else moves.

[chenxiaolong]

Thanks!