Enable private groups in production

briar-desktop/src/main/kotlin/org/briarproject/briar/desktop/DesktopModule.kt

@@ -54,7 +54,7 @@ internal class DesktopModule {
     @Provides
     @Singleton
     internal fun provideDesktopFeatureFlags() = object : DesktopFeatureFlags {
-        override fun shouldEnablePrivateGroups() = false
+        override fun shouldEnablePrivateGroups() = true
         override fun shouldEnableForums() = true
         override fun shouldEnableBlogs() = false
         override fun shouldEnableTransportSettings() = false