docs(distro-vertx) Typo in  example.
# Convenience script to launch apiman's Vert.x gateway with sensible
# default behaviour.
+#
# To pass additional Java options with $APIMAN_GATEWAY_OPTS.
-# e.g. export APIMAN_GATEWAY_OPTS="-Xmx2048".
+# e.g. export APIMAN_GATEWAY_OPTS="-Xmx2048m".
# Some elements cribbed from WF's `standalone.sh`; thanks.
DIRNAME=$(dirname "$0")
