help.c: use SHELL_PATH instead of hard-coded "/bin/sh"

diff --git a/RelNotes b/RelNotes
index 76462ab9e8ed2f4896f683d3cceafb28781e9101..689db12994adff4279d335ff75207026f1fdd8ec 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.0.4.txt
\ No newline at end of file
+Documentation/RelNotes/2.3.2.txt
\ No newline at end of file