SECURITY.md: Avoid needing to update tcnative table every release
SECURITY.md: Avoid needing to update tcnative table every release

This also fixes an oversight for the 1.0.2+ releases, since they had a
different netty version.

elandau/grpc-java,elandau/grpc-java,grpc/grpc-java,carl-mastrangelo/grpc-java,rmichela/grpc-java,stanley-cheung/grpc-java,stanley-cheung/grpc-java,dapengzhang0/grpc-java,grpc/grpc-java,ejona86/grpc-java,elandau/grpc-java,dapengzhang0/grpc-java,dapengzhang0/grpc-java,rmichela/grpc-java,carl-mastrangelo/grpc-java,ejona86/grpc-java,zhangkun83/grpc-java,ejona86/grpc-java,stanley-cheung/grpc-java,dapengzhang0/grpc-java,ejona86/grpc-java,carl-mastrangelo/grpc-java,rmichela/grpc-java,carl-mastrangelo/grpc-java,zhangkun83/grpc-java,zhangkun83/grpc-java,grpc/grpc-java,zhangkun83/grpc-java,stanley-cheung/grpc-java,elandau/grpc-java,rmichela/grpc-java,grpc/grpc-java