1.6 release: Disable using keychain on macOS by default

It shows a ton of popups when it's used for the first time (or every
time if "Always allow" is not granted), it's really annoying to use at
this state.

modules/Lith/Core/settings.h

@@ -108,7 +108,11 @@ class LITHCORE_EXPORT Settings : public QObject {
     SETTING(bool, openLinksDirectly, false)
     SETTING(bool, openLinksDirectlyInBrowser, false)
 
+#ifdef Q_OS_MACOS
+    SETTING(bool, encryptedCredentials, false)
+#else
     SETTING(bool, encryptedCredentials, true)
+#endif
     Q_PROPERTY(bool credentialEncryptionAvailable READ credentialEncryptionAvailable CONSTANT)
     static bool credentialEncryptionAvailable();