fix maven plugin snapshot version

Author: wing328

modules/openapi-generator-maven-plugin/examples/kotlin.xml

@@ -15,7 +15,7 @@
 				<groupId>org.openapitools</groupId>
 				<artifactId>openapi-generator-maven-plugin</artifactId>
 				<!-- RELEASE_VERSION -->
-				<version>4.3.0-SNAPSHOT</version>
+				<version>5.0.0-SNAPSHOT</version>
 				<!-- /RELEASE_VERSION -->
 				<executions>
 					<execution>