Duplicate message code within message.properties file

There are three codes within the message properties file that have been mistakenly duplicated. IN each case, one of the duplicates must be removed.

• install.error.unableCreateDb
• Provider.title (duplicate is lowercase: provider.title)
• Encounter.edit

Ideally, any code using these duplicates would be checked and fixed if necessary (e.g., adding a non-duplicating message code if appropriate); however, I don't think this should keep us from correcting these duplicates, especially because we cannot use Amanuens for translating our message bundles in trunk until these duplicates are removed.