swift framwork module compatibility

remove this include to be compatible with swift framework in pods

src/extra/fts3/fts3_tokenizer.h

@@ -24,7 +24,6 @@
 ** If tokenizers are to be allowed to call sqlite3_*() functions, then
 ** we will need a way to register the API consistently.
 */
-#include "sqlite3.h"
 
 /*
 ** Structures used by the tokenizer interface. When a new tokenizer