PluginInstallWizard: Remove unneeded code

Remove an unneeded `if` and actually no need to override a method that
just calls the parent implementation.

Change-Id: I9f17ed1587227ce8f0ba14cdeb72dd32b73513ba
Reviewed-by: hjk <hjk@qt.io>

src/plugins/coreplugin/plugininstallwizard.cpp

@@ -112,13 +112,6 @@ public:
         return bool(sourceAndCommand);
     }
 
-    int nextId() const final
-    {
-        if (hasLibSuffix(m_data->sourcePath))
-            return WizardPage::nextId();
-        return WizardPage::nextId();
-    }
-
     InfoLabel *m_info = nullptr;
     Data *m_data = nullptr;
 };