Revert "Switch to alarm manager for more control over polling"

This reverts commit 7658047300.

app/src/main/java/eu/faircode/email/ServiceTileUnseen.java

@@ -20,6 +20,7 @@ package eu.faircode.email;
 */
 
 import android.annotation.TargetApi;
+import android.content.Context;
 import android.content.Intent;
 import android.graphics.drawable.Icon;
 import android.os.Build;
@@ -96,6 +97,12 @@ public class ServiceTileUnseen extends TileService {
 
     public void onClick() {
         Log.i("Click tile unseen");
-        ServiceSynchronize.poll(this, null);
+        final Context context = getApplicationContext();
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                WorkerPoll.sync(context, null);
+            }
+        }).start();
     }
 }