Merge pull request #4096 from jboeuf/update_ssl_cert

src/core/tsi/test_creds/server1.pem

src/csharp/Grpc.IntegrationTesting/data/server1.pem

src/node/test/data/server1.pem

src/php/tests/data/server1.pem

src/python/grpcio_test/grpc_interop/credentials/server1.pem

src/python/grpcio_test/grpc_test/credentials/server1.pem

src/ruby/spec/testdata/server1.pem

test/core/end2end/data/server1_cert.c