ISSUE-2969 fix path to register resource handler to work SwaggerIndexPageTransformer considering /webjar path prefix

Author: lagoshny

springdoc-openapi-starter-webflux-ui/src/main/java/org/springdoc/webflux/ui/SwaggerWebFluxConfigurer.java

@@ -106,7 +106,7 @@ public void addResourceHandlers(ResourceHandlerRegistry registry) {
 		String resourcePath,swaggerUiPrefix;
 
 		if (DEFAULT_WEB_JARS_PREFIX_URL.equals(webjarsPrefix)) {
-			swaggerUiPrefix = SWAGGER_UI_PREFIX;
+			swaggerUiPrefix = webjarsPrefix + SWAGGER_UI_PREFIX;
 			resourcePath = webjarsPrefix + SWAGGER_UI_PREFIX + DEFAULT_PATH_SEPARATOR + swaggerUiConfigProperties.getVersion() + DEFAULT_PATH_SEPARATOR;
 		} else {
 			swaggerUiPrefix = webjarsPrefix;