Update ezSearchBoostrapper.cs

Remove force field values to lower case.

The Umbraco ExternalSearcher analyser (based on the Lucene standard analyser I believe) already applies a lowercase filter so this is not necessary. Forcing the field values to lower case breaks other packages (e..g uBlogsy)
Merge pull request #5 from DougMac/patch-2

Update ezSearchBoostrapper.cs