Update log message for empty env variable (#6115)

Co-authored-by: Jared Rhizor <[email protected]>

Author: tuliren

airbyte-config/models/src/main/java/io/airbyte/config/EnvConfigs.java

@@ -424,7 +424,7 @@ private <T> T getEnvOrDefault(final String key, final T defaultValue, final Func
     if (value != null && !value.isEmpty()) {
       return parser.apply(value);
     } else {
-      LOGGER.info("{} not found or empty, defaulting to {}", key, isSecret ? "*****" : defaultValue);
+      LOGGER.info("Using default value for environment variable {}: '{}'", key, isSecret ? "*****" : defaultValue);
       return defaultValue;
     }
   }