Add message when player is kicked out of Super Gravitron

The player gets kicked out of the Super Gravitron if they have
invincibility or slowdown enabled. However, this can be confusing if no
message pops up
( https://steamcommunity.com/app/70300/discussions/0/3039355280230178910/ )
. So I've made it so that a text box will pop up when they get kicked
out.

desktop_version/src/Game.cpp

@@ -813,6 +813,10 @@ void Game::updatestate(void)
             if (!map.custommode && nocompetitive())
             {
                 returntolab();
+
+                startscript = true;
+                newscript = "disableaccessibility";
+
                 state = 0;
                 break;
             }

desktop_version/src/Scripts.cpp

@@ -6724,6 +6724,26 @@ void scriptclass::load(const std::string& name)
         };
         filllines(lines);
     }
+    else if (SDL_strcmp(t, "disableaccessibility") == 0)
+    {
+        static const char* lines[] = {
+        "cutscene()",
+        "untilbars()",
+
+        "squeak(terminal)",
+        "text(gray,0,114,3)",
+        "Please disable invincibility",
+        "and/or slowdown before entering",
+        "the Super Gravitron.",
+        "position(center)",
+        "speak",
+
+        "endtext",
+        "endcutscene()",
+        "untilbars()",
+        };
+        filllines(lines);
+    }
     else
     {
         loadother(t);