Fixed a dependency version in a karaf test module. (#12399)

test/servlet-containers/karaf/vaadin-karaf-bundle1/pom.xml

@@ -43,7 +43,7 @@
         <dependency>
             <groupId>com.vaadin</groupId>
             <artifactId>vaadin-osgi-integration</artifactId>
-            <version>8.1.0.beta1</version>
+            <version>${vaadin.version}</version>
             <scope>provided</scope>
         </dependency>
         <dependency>