Allow for building without QtKeychain (#3318)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/widgets/settingspages/AboutPage.cpp

@@ -140,9 +140,11 @@ AboutPage::AboutPage()
             addLicense(form.getElement(), "Websocketpp",
                        "https://www.zaphoyd.com/websocketpp/",
                        ":/licenses/websocketpp.txt");
+#ifndef NO_QTKEYCHAIN
             addLicense(form.getElement(), "QtKeychain",
                        "https://github.com/frankosterfeld/qtkeychain",
                        ":/licenses/qtkeychain.txt");
+#endif
             addLicense(form.getElement(), "lrucache",
                        "https://github.com/lamerman/cpp-lru-cache",
                        ":/licenses/lrucache.txt");

src/widgets/settingspages/GeneralPage.cpp

@@ -584,7 +584,7 @@ void GeneralPage::initLayout(GeneralPageView &layout)
 
     layout.addCheckbox("Restart on crash", s.restartOnCrash);
 
-#ifdef Q_OS_LINUX
+#if defined(Q_OS_LINUX) && !defined(NO_QTKEYCHAIN)
     if (!getPaths()->isPortable())
     {
         layout.addCheckbox(