Revert "Record max idle time"

This reverts commit d11d15d771.

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

@@ -3308,22 +3308,6 @@ class Core {
                 }
         }
 
-        private long maxIdle = 0;
-        private long lastActivity = 0;
-
-        synchronized void activity() {
-            long now = SystemClock.elapsedRealtime();
-            if (lastActivity > 0 && now - lastActivity > maxIdle) {
-                maxIdle = now - lastActivity;
-                Log.i("Max idle=" + (maxIdle / 1000));
-            }
-            lastActivity = now;
-        }
-
-        long getMaxIdle() {
-            return maxIdle;
-        }
-
         @NonNull
         @Override
         public String toString() {

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

@@ -1020,7 +1020,6 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                                         while (ifolder.isOpen() && state.isRunning() && state.isRecoverable()) {
                                             Log.i(folder.name + " do idle");
                                             ifolder.idle(false);
-                                            state.activity();
                                         }
                                     } catch (Throwable ex) {
                                         Log.e(folder.name, ex);