sdl: vid: allow to build with earlier versions of SDL2

engine/platform/sdl/vid_sdl.c

@@ -733,9 +733,13 @@ int GL_SetAttribute( int attr, int val )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_FLAGS );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_SHARE_WITH_CURRENT_CONTEXT );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_FRAMEBUFFER_SRGB_CAPABLE );
+#if SDL_VERSION_ATLEAST( 2, 0, 4 )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_RELEASE_BEHAVIOR );
+#endif
+#if SDL_VERSION_ATLEAST( 2, 0, 6 )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_RESET_NOTIFICATION );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_NO_ERROR );
+#endif
 	case REF_GL_CONTEXT_PROFILE_MASK:
 #ifdef SDL_HINT_OPENGL_ES_DRIVER
 		if (val == REF_GL_CONTEXT_PROFILE_ES)
@@ -770,9 +774,13 @@ int GL_GetAttribute( int attr, int *val )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_FLAGS );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_SHARE_WITH_CURRENT_CONTEXT );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_FRAMEBUFFER_SRGB_CAPABLE );
+#if SDL_VERSION_ATLEAST( 2, 0, 4 )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_RELEASE_BEHAVIOR );
+#endif
+#if SDL_VERISON_ATLEAST( 2, 0, 6 )
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_RESET_NOTIFICATION );
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_NO_ERROR );
+#endif
 		MAP_REF_API_ATTRIBUTE_TO_SDL( GL_CONTEXT_PROFILE_MASK );
 #undef MAP_REF_API_ATTRIBUTE_TO_SDL
 	}