Small improvement

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

@@ -136,7 +136,7 @@ public class ApplicationEx extends Application
         });
 
         if (BuildConfig.DEBUG &&
-                Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.P && false) {
             StrictMode.VmPolicy policy = new StrictMode.VmPolicy.Builder(StrictMode.getVmPolicy())
                     .detectNonSdkApiUsage()
                     .penaltyListener(getMainExecutor(), new StrictMode.OnVmViolationListener() {
@@ -204,7 +204,10 @@ public class ApplicationEx extends Application
 
         try {
             boolean tcp_keep_alive = prefs.getBoolean("tcp_keep_alive", false);
-            System.setProperty("fairemail.tcp_keep_alive", Boolean.toString(tcp_keep_alive));
+            if (tcp_keep_alive)
+                System.setProperty("fairemail.tcp_keep_alive", Boolean.toString(tcp_keep_alive));
+            else
+                System.clearProperty("fairemail.tcp_keep_alive");
         } catch (Throwable ex) {
             Log.e(ex);
         }

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

@@ -286,11 +286,11 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                 try {
+                    prefs.edit().putBoolean("tcp_keep_alive", checked).apply();
                     if (checked)
                         System.setProperty("fairemail.tcp_keep_alive", Boolean.toString(checked));
                     else
                         System.clearProperty("fairemail.tcp_keep_alive");
-                    prefs.edit().putBoolean("tcp_keep_alive", checked).apply();
                 } catch (Throwable ex) {
                     Log.e(ex);
                 }