Fix Travis CI nightly deploy

I have no idea why this doesn't work anymore. I didn't even touch that
line when I added the test build stuff...

Author: asarium

.travis.yml

@@ -48,7 +48,7 @@ deploy:
           tags: true
 
     - provider: script
-      script: ci/travis/ftp_deploy.sh
+      script: bash ci/travis/ftp_deploy.sh
       on:
           condition: '"$NIGHTLY_BUILD" == true'
           tags: true