Roll back maven-invoker-plugin 3.1.0->3.0.1

A bug exists in maven-invoker-plugin 3.1.0 which causes the maven-plugin
module to fail to build, due to missing SNAPSHOT dependencies copied
into the PluginIT's local repository from sibling modules. This is
because transitive dependencies fail to be copied, as they were in 3.0.1
of the plugin.

See https://issues.apache.org/jira/browse/MINVOKER-243
diff --git a/src/it/settings.xml b/src/it/settings.xml
index c8f77f0..abf9583 100644
--- a/src/it/settings.xml
+++ b/src/it/settings.xml
@@ -20,12 +20,11 @@
 -->
 
 <settings>
+  <!-- This allows the invoked Maven to use the normal local repo as an additional "remote" repo -->
+  <!-- see also https://maven.apache.org/plugins/maven-invoker-plugin/examples/fast-use.html -->
   <profiles>
     <profile>
       <id>it-repo</id>
-      <activation>
-        <activeByDefault>true</activeByDefault>
-      </activation>
       <repositories>
         <repository>
           <id>local.central</id>
@@ -52,4 +51,7 @@
       </pluginRepositories>
     </profile>
   </profiles>
+  <activeProfiles>
+    <activeProfile>it-repo</activeProfile>
+  </activeProfiles>
 </settings>