chore: fix the lint

Author: minherz

src/test/java/com/google/cloud/logging/logback/LoggingAppenderTest.java

@@ -34,7 +34,6 @@
 import com.google.cloud.logging.Logging;
 import com.google.cloud.logging.Logging.WriteOption;
 import com.google.cloud.logging.LoggingEnhancer;
-import com.google.cloud.logging.LoggingOptions;
 import com.google.cloud.logging.Payload;
 import com.google.cloud.logging.Severity;
 import com.google.common.collect.ImmutableList;