[swift-settings] Increment the module format.

I forgot to do this in b34e2d7. This is just to
be careful.

Author: gottesmm

lib/Serialization/ModuleFormat.h

@@ -58,7 +58,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 947; // @preEnumExtensibility attribute
+const uint16_t SWIFTMODULE_VERSION_MINOR = 948; // remove SwiftSettings
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///