Fix an issue in the test8.c test module that arises because of the change

to PRAGMA index_list().  Remove an unused local variable.

FossilOrigin-Name: 029430c503f243a34439698779db7e591cfbe126

src/test8.c

@@ -265,6 +265,7 @@ static int getIndexArray(
   while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
     const char *zIdx = (const char *)sqlite3_column_text(pStmt, 1);
     sqlite3_stmt *pStmt2 = 0;
+    if( zIdx==0 ) continue;
     zSql = sqlite3_mprintf("PRAGMA index_info(%s)", zIdx);
     if( !zSql ){
       rc = SQLITE_NOMEM;