Attempt to resolve intents for external activities before trying to s…

…tart them

Facebook is now attempting to force users to install the Facebook Messenger app by trying to start an activity with an implicit intent, which isn't found by the system and will crash if not handled properly.

Fixes #83
Fixes #84

app/src/main/java/com/danvelazco/fbwrapper/activity/BaseFacebookWebViewActivity.java

@@ -636,7 +636,10 @@ public void openExternalSite(String url) {
         // This link is not for a page on my site, launch another Activity
         // that handles this URL
         Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
-        startActivity(intent);
+
+        if (intent.resolveActivity(getPackageManager()) != null) {
+            startActivity(intent);
+        }
     }
 
     /**