plugins/sql: fix doc formatting for tables with multiple indices.

Before vs after:

   - `forwards` indexed by `in_channel and in_htlc_id` (see lightning-listforwards(7))
   - `forwards` indexed by `in_channel` and `in_htlc_id` (see lightning-listforwards(7))

And:
   - `htlcs` indexed by `short_channel_id and id` (see lightning-listhtlcs(7))
   - `htlcs` indexed by `short_channel_id` and `id` (see lightning-listhtlcs(7))

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

plugins/sql.c

@@ -1581,16 +1581,16 @@ static const char *fmt_indexes(const tal_t *ctx, const char *table)
 		assert(!ret);
 		BUILD_ASSERT(ARRAY_SIZE(indices[i].fields) == 2);
 		if (indices[i].fields[1])
-			ret = tal_fmt(tmpctx, "%s and %s",
+			ret = tal_fmt(tmpctx, "`%s` and `%s`",
 				      indices[i].fields[0],
 				      indices[i].fields[1]);
 		else
-			ret = tal_fmt(tmpctx, "%s",
+			ret = tal_fmt(tmpctx, "`%s`",
 				      indices[i].fields[0]);
 	}
 	if (!ret)
 		return "";
-	return tal_fmt(ctx, " indexed by `%s`", ret);
+	return tal_fmt(ctx, " indexed by %s", ret);
 }
 
 static const char *json_prefix(const tal_t *ctx,