Revert "Invert condition for testing purposes"

This reverts commit 587cd34.

Author: reakaleek

.github/workflows/preview-build.yml

@@ -66,7 +66,7 @@ jobs:
       - run: |
           case "${GITHUB_EVENT_NAME}" in
             "pull_request" | "pull_request_target")
-              if [[ "${AUTHOR_ASSOCIATION}" != "MEMBER" ]]; then
+              if [[ "${AUTHOR_ASSOCIATION}" == "MEMBER" ]]; then
                 exit 0;
               else
                 echo "::error::You must be a member of the elastic organization to trigger a preview build. Please ask a member of the elastic organization to review your PR and re-trigger the build.";