Bump org.apache.maven.plugins:maven-war-plugin from 2.3 to 3.4.0

Bumps [org.apache.maven.plugins:maven-war-plugin](https://github.com/apache/maven-war-plugin) from 2.3 to 3.4.0.
- [Commits](apache/maven-war-plugin@maven-war-plugin-2.3...maven-war-plugin-3.4.0)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-war-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

blueprint/examples/blueprint-sample-war/pom.xml

@@ -50,7 +50,7 @@
         <blueprint.web.version>1.0.0</blueprint.web.version>
         <geronimo-servlet_2.5_spec.version>1.2</geronimo-servlet_2.5_spec.version>
         <jetty-maven-plugin.version>8.1.8.v20121106</jetty-maven-plugin.version>
-        <maven-war-plugin.version>2.3</maven-war-plugin.version>
+        <maven-war-plugin.version>3.4.0</maven-war-plugin.version>
         <tomcat6-maven-plugin.version>2.0</tomcat6-maven-plugin.version>
         <tomcat7-maven-plugin.version>2.0</tomcat7-maven-plugin.version>
     </properties>