sha1_file.c: use ALLOC_GROW() in pretend_sha1_file()

diff --git a/RelNotes b/RelNotes
index 0064299c0e0cbe3e133d4464f2ab65d89324a0ab..bb52cf9476df53ddb9788f16082e2e92e76a4db5 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.8.5.1.txt
\ No newline at end of file
+Documentation/RelNotes/1.9.0.txt
\ No newline at end of file