options: flip listenonion to false if not listening

If the user has unchecked "Allow incoming connections" in
`Settings->Options...->Network` then `fListen=false` is saved in
`~/.config/Bitcoin/Bitcoin-Qt.conf`. This flips `-listen` to `false`
during startup, but leaves `-listenonion` to `true`.

This flipping of `-listen` is done in `OptionsModel::Init()` after
`InitParameterInteraction()` has been executed which would have flipped
`-listenonion`, should it have seen `-listen` being `false`
(this is a difference between `bitcoind` and `bitcoin-qt`).

Fixes: bitcoin-core/gui#567

Author: vasild

src/qt/optionsmodel.cpp

@@ -154,8 +154,11 @@ void OptionsModel::Init(bool resetSettings)
 
     if (!settings.contains("fListen"))
         settings.setValue("fListen", DEFAULT_LISTEN);
-    if (!gArgs.SoftSetBoolArg("-listen", settings.value("fListen").toBool()))
+    if (!gArgs.SoftSetBoolArg("-listen", settings.value("fListen").toBool())) {
         addOverriddenOption("-listen");
+    } else if (!settings.value("fListen").toBool()) {
+        gArgs.SoftSetBoolArg("-listenonion", false);
+    }
 
     if (!settings.contains("server")) {
         settings.setValue("server", false);