Remove the archetypeRepository property from the mvn archetype:generate

When working with released artifacts there is no need to specify an
archetype repository.

Change-Id: Ib3010e1b08d361ae663f9cd3b3a412826f262cf4
diff --git a/Documentation/dev-plugins.txt b/Documentation/dev-plugins.txt
index cb3c944..e619923 100644
--- a/Documentation/dev-plugins.txt
+++ b/Documentation/dev-plugins.txt
@@ -37,7 +37,6 @@
 mvn archetype:generate -DarchetypeGroupId=com.google.gerrit \
     -DarchetypeArtifactId=gerrit-plugin-archetype \
     -DarchetypeVersion=2.10 \
-    -DarchetypeRepository=https://oss.sonatype.org/content/repositories/releases/ \
     -DgroupId=com.googlesource.gerrit.plugins.testplugin \
     -DartifactId=testplugin
 ----