don't override newer managed version 30 (#12)

diff --git a/doxia-integration-tools/pom.xml b/doxia-integration-tools/pom.xml
index dabf9b3..37b6636 100644
--- a/doxia-integration-tools/pom.xml
+++ b/doxia-integration-tools/pom.xml
@@ -95,7 +95,6 @@
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-container-default</artifactId>
-      <version>1.0-alpha-9</version>
     </dependency>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>