Drop building internal docs

They are causing the Jenkins release job to fail and no one really cares
about those

Change-Id: I6c4bd7923dd85772c6fd678fafb172b875e27b8a
diff --git a/tools/build/onos-release b/tools/build/onos-release
index ae638fa..af2ade8 100755
--- a/tools/build/onos-release
+++ b/tools/build/onos-release
@@ -33,7 +33,7 @@
 bazel build onos
 
 # Build ONOS docs
-bazel build //docs:internal //docs:external
+bazel build //docs:external
 
 if [ $dryRun -eq 0 ]; then
     publish_url="oss.sonatype.org"