run.sh: fix -s switch

fixes bug introduced in 87b3803d4661b09a433fda9f89f00e690809f022 (new
'--disable-open-browser' option)

Signed-off-by: Thomas Stilwell <stilwellt@openlabs.co>
Merge pull request #453 from benemorius/seed-switch

run.sh: fix -s switch