site/landing: Don't minify when serving locally

There's a bug in hugo that prevents the minifier from working with our
SVGs, it ends up corrupting them. Disable it when serving locally, as
it's already disabled when deploying.

Signed-off-by: Garret Kelly <gdk@google.com>
diff --git a/site/landing/serve.sh b/site/landing/serve.sh
index 371cb37..30457a7 100755
--- a/site/landing/serve.sh
+++ b/site/landing/serve.sh
@@ -5,4 +5,4 @@
 
 set -e
 
-hugo --minify -D server
+hugo -D server