Don't ignore non-virtual NSC_EXTRA columns in ef_verify.c

These are commonly timestamps (no verification implemented), or
aliases for a non-extra column (which gets verified).  Commit 49780e2c
(v4.3.12) added the exception: EF_SECTOR's uid.  Proof by example that
ignoring these columns is wrong.  Fix: ignore only virtual columns.

src/lib/common/ef_verify.c

@@ -114,8 +114,8 @@ verify_row(int type, int row)
     }
 
     for (i = 0; ca[i].ca_name; ++i) {
-	if (ca[i].ca_flags & NSC_EXTRA)
-	    continue;
+	if (ca[i].ca_get)
+	    continue;		/* virtual */
 	n = ca[i].ca_type != NSC_STRINGY ? ca[i].ca_len : 0;
 	j = 0;
 	do {