Fix binding 'context menu' key using SDL2

SDL 1.2 converted Windows' VK_APPS and X11 XK_Hyper_R to SDLK_MENU.
SDL2 has it as a separate SDLK_APPLICATION key, so convert it to K_MENU too.

code/sdl/sdl_input.c

@@ -266,6 +266,7 @@ static keyNum_t IN_TranslateSDLToQ3Key( SDL_Keysym *keysym, qboolean down )
 			case SDLK_PRINTSCREEN:  key = K_PRINT;         break;
 			case SDLK_SYSREQ:       key = K_SYSREQ;        break;
 			case SDLK_MENU:         key = K_MENU;          break;
+			case SDLK_APPLICATION:	key = K_MENU;          break;
 			case SDLK_POWER:        key = K_POWER;         break;
 			case SDLK_UNDO:         key = K_UNDO;          break;
 			case SDLK_SCROLLLOCK:   key = K_SCROLLOCK;     break;