adding version to shade in oecfg/pom.xml

Change-Id: I406196c84949fc0a6dabf529deea0aab388b2011

@@ -49,6 +49,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
+                <version>2.3</version>
                 <executions>
                     <execution>
                         <phase>package</phase>