fix: Correct identifier for upsert-kafka-safe connector (#307)

Author: ferenc-csaky

connectors/kafka-safe-connector/src/main/java/org/apache/flink/streaming/connectors/kafka/table/SafeUpsertKafkaDynamicTableFactory.java

@@ -85,7 +85,7 @@
 public class SafeUpsertKafkaDynamicTableFactory
         implements DynamicTableSourceFactory, DynamicTableSinkFactory {
 
-    public static final String IDENTIFIER = "upsert-kafka";
+    public static final String IDENTIFIER = "upsert-kafka-safe";
 
     @Override
     public String factoryIdentifier() {