Fixed wrong application property specified in documentation for the server generator

Application property used for specifying input base directory currently faulty and is now updated.

Author: rednalyn

docs/modules/ROOT/pages/includes/server-getting-started.adoc

@@ -47,7 +47,7 @@ IMPORTANT: it is relative to the project base directory. For example, if you hav
 
 [source,properties]
 ----
-quarkus.openapi.input-base-dir=openapi-definitions
+quarkus.openapi.generator.input-base-dir=openapi-definitions
 ----
 
 If a base package name is not provided, it will be used the default `io.apicurio.api`. You can customize it with the following property:
@@ -144,4 +144,4 @@ public class PetStoreImpl implements PetResource {
 }
 ----
 
-See the https://github.com/quarkiverse/quarkus-openapi-generator/tree/main/server/integration-tests[integration-tests] module for more information of how to use this extension. Please be advised that the extension is on experimental, early development stage.
+See the https://github.com/quarkiverse/quarkus-openapi-generator/tree/main/server/integration-tests[integration-tests] module for more information of how to use this extension. Please be advised that the extension is on experimental, early development stage.