Fix segfault on x11

main/SCsub

@@ -121,7 +121,7 @@ def make_default_controller_mappings(target, source, env):
             g.write("\t\"{}\",\n".format(mapping))
         g.write("#endif\n")
 
-    g.write("};\n")
+    g.write("\tNULL\n};\n")
     g.close()
 
 env.main_sources = []