Fix for non-framework build

[Udumft]

Fixed a mistype that prevented building SQLite.swift as non-framework sources.

Steps to reproduce:

• download the source
• create new XCode project
• add SQLite.swift sources inside new project (just sources, not the actual .xcodeproj file)
• build.

As result: sources are built as is and no framework is created -> reference to SQLite. becomes invalid.
Keeping in mind that Setter is referenced in this file earlier I assume this is a mistype.

[jberkel]

thanks!