Fix cat vs echo bug

Author: mhucka

dev_tools/ci/size-labeler.sh

@@ -98,7 +98,7 @@ function api_call() {
     set -e
     if [[ $exit_status -ne 0 ]]; then
         error "GitHub API call failed (curl exit $exit_status) for ${url}"
-        cat "${response_body}"
+        echo "${response_body}"
         exit $exit_status
     fi
     echo "${response_body}"