GUI: hide SCV once again

after the unification the system ID and chan count are stable
however, the system is still beta...
it won't be ready by 0.6.8 so I am going to hide it

src/gui/gui.h

@@ -74,7 +74,7 @@
 #define FM_PREVIEW_SIZE 512
 
 #define CHECK_HIDDEN_SYSTEM(x) \
-  (x==DIV_SYSTEM_YMU759 || x==DIV_SYSTEM_DUMMY || x==DIV_SYSTEM_SEGAPCM_COMPAT || x==DIV_SYSTEM_PONG)
+  (x==DIV_SYSTEM_YMU759 || x==DIV_SYSTEM_DUMMY || x==DIV_SYSTEM_SEGAPCM_COMPAT || x==DIV_SYSTEM_PONG || x==DIV_SYSTEM_UPD1771C)
 
 enum FurnaceGUIRenderBackend {
   GUI_BACKEND_SDL=0,

src/gui/presets.cpp

@@ -1568,11 +1568,6 @@ void FurnaceGUI::initSystemPresets() {
       )
     }
   );
-  ENTRY(
-    "Epoch Super Cassette Vision", {
-      CH(DIV_SYSTEM_UPD1771C, 1.0f, 0, "")
-    }
-  );
   CATEGORY_END;
 
   CATEGORY_BEGIN(_("Arcade systems"),_("INSERT COIN"));