Try to fix harmless compiler warnings reported by Fortify.

FossilOrigin-Name: e0fa6fdc14ac5458f9200cbae124f8025ea534ea
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 7a5d225..5d72295 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3364,7 +3364,7 @@
 #else
 # define sqlite3FileSuffix3(X,Y)
 #endif
-u8 sqlite3GetBoolean(const char *z,int);
+u8 sqlite3GetBoolean(const char *z,u8);
 
 const void *sqlite3ValueText(sqlite3_value*, u8);
 int sqlite3ValueBytes(sqlite3_value*, u8);