Don't try to commit tags if doing a dry run

Change-Id: I967d6502f6e8cbcefc915f51224c140f418002f6
diff --git a/tools/build/onos-release b/tools/build/onos-release
index e841b3a..621d5fe 100755
--- a/tools/build/onos-release
+++ b/tools/build/onos-release
@@ -60,8 +60,10 @@
     popd
 fi
 
-# Commit newly versioned artifacts and issue a tag.
-git commit -a -m"Tagging $NEW_VERSION"
-git tag -sm"Tagging $NEW_VERSION" $NEW_VERSION #signed tag
+if [ $dryRun -eq 0 ]; then
+    # Commit newly versioned artifacts and issue a tag.
+    git commit -a -m"Tagging $NEW_VERSION"
+    git tag -sm"Tagging $NEW_VERSION" $NEW_VERSION #signed tag
+fi
 
 # TODO: push?