Update readme for compute sendgrid
Update readme for compute sendgrid

the link was wrong
jetty-project/java-docs-samples,GoogleCloudPlatform/java-docs-samples,jetty-project/java-docs-samples,tswast/java-docs-samples,tswast/java-docs-samples,jetty-project/java-docs-samples,jetty-project/java-docs-samples,ErinJoan/mostly_empty_directory,GoogleCloudPlatform/java-docs-samples,ErinJoan/mostly_empty_directory,GoogleCloudPlatform/java-docs-samples,ErinJoan/mostly_empty_directory,GoogleCloudPlatform/java-docs-samples,tswast/java-docs-samples,tswast/java-docs-samples,GoogleCloudPlatform/java-docs-samples,jetty-project/java-docs-samples,ErinJoan/mostly_empty_directory,GoogleCloudPlatform/java-docs-samples