[Dovecot] sieve header :matches for multiline header

RFC3028 say:

Folding of long header lines (as described in [IMAIL] 3.4.8) is
removed prior to interpretation of the data.  The folding syntax (the
CRLF that ends a line plus any leading whitespace at the beginning of
the next line that indicates folding) are interpreted as if they were
a single space.

But it seems to be not true for dovecot-sieve-1.0.2

for header

Received: from example.ru (example.ru [192.168.105.14]) by myserver (Postfix) with ESMTP id D4DA5D85927

This sieve test work:

header :matches "Received" "from *by myserver (Postfix) with ESMTP id *"

But this test not work, while should also work according to RFC:

header :matches "Received" "from * by myserver (Postfix) with ESMTP id *"

-- WBR, Anton Yuzhaninov