fix exception caused by same types registered multiple times

Author: arnaud-daroussin

modules/scala-api/src/main/scala/org/apache/flinkx/api/StreamExecutionEnvironment.scala

@@ -967,7 +967,8 @@ object StreamExecutionEnvironment {
   }
 
   private def configureFailFastOnScalaTypeResolutionWithClass(configuration: Configuration): Unit = {
-    if (!isFailFastOnScalaTypeResolutionWithClassDisabled) {
+    if (!isFailFastOnScalaTypeResolutionWithClassConfigured && !isFailFastOnScalaTypeResolutionWithClassDisabled) {
+      isFailFastOnScalaTypeResolutionWithClassConfigured = true
       val serializationOption = ConfigOptions.key("pipeline.serialization-config").stringType().asList().noDefaultValue()
       val serializationConfig = configuration.getOptional(serializationOption).orElse(new util.ArrayList[String])
       serializationConfig.add("scala.Product: {type: typeinfo, class: org.apache.flinkx.api.typeinfo.FailFastTypeInfoFactory}")
@@ -979,6 +980,8 @@ object StreamExecutionEnvironment {
     }
   }
 
+  private var isFailFastOnScalaTypeResolutionWithClassConfigured: Boolean = false
+
   private lazy val isFailFastOnScalaTypeResolutionWithClassDisabled: Boolean =
     sys.env
       .get("DISABLE_FAIL_FAST_ON_SCALA_TYPE_RESOLUTION_WITH_CLASS")