Only push the Lua error handler once

src/script/cpp_api/s_base.cpp

src/script/cpp_api/s_base.h

src/script/cpp_api/s_entity.cpp

src/script/cpp_api/s_inventory.cpp

src/script/cpp_api/s_item.cpp

src/script/cpp_api/s_mainmenu.cpp

src/script/cpp_api/s_node.cpp

src/script/cpp_api/s_nodemeta.cpp

src/script/cpp_api/s_server.cpp