ParsoidConfig: Replace "-" with "_" to get dbName for wikis

* Without this, we need to add special config entries to localsettings.js
  on production.
* Ex: http://localhost:8000/nds_nlwiki/Westerveld will not resolve
  without this patch or an entry in localsettings.js to point to
  nds-nl.wikipedia.org

Change-Id: I7ddce922dc207429b1843da8da23009b05f89ffb
Merge "ParsoidConfig: Replace "-" with "_" to get dbName for wikis"