gnucash-on-windows master: Fix boost detection with autotools

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash-on-windows/commit/fdf048d0 (commit)
	from  https://github.com/Gnucash/gnucash-on-windows/commit/5de8f8be (commit)



commit fdf048d0dc234089b0dae40248c9198718d1fc13
Author: Geert Janssens <geert at kobaltwit.be>
Date:   Wed Feb 8 11:50:29 2017 +0100

    Fix boost detection with autotools
    
    Turns out when BOOST_DIR is set in the environment
    the m4 macro looks for boost in BOOST_DIR/staging.
    Not what I expected. To have it look in the root
    of the installed directory, we need ac_boost_dir. However
    our cmake files do look in BOOST_DIR. So I'm simply
    setting both here.



Summary of changes:
 install-impl.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)