Handle an SQLITE_IGNORE returned when requesting authorization to read parent key columns by pretending the parent key columns contain NULL values.

FossilOrigin-Name: 3c24df38e6ae5dfe999bbf3133b65df0074c6a50
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a82bbdf..03ff1be 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2734,7 +2734,7 @@
   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
   void sqlite3AuthContextPop(AuthContext*);
-  void sqlite3AuthReadCol(Parse*, const char *, const char *, int, Expr *);
+  int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
 #else
 # define sqlite3AuthRead(a,b,c,d)
 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK